diff --git a/frontend/src/components/BuyDialog.tsx b/frontend/src/components/BuyDialog.tsx
index c0bd566..33c85ba 100644
--- a/frontend/src/components/BuyDialog.tsx
+++ b/frontend/src/components/BuyDialog.tsx
@@ -9,6 +9,7 @@ import {
     Box,
 } from '@mui/material';
 import { NewStock } from '../types/types';
+import BuyExpDateSelect from './BuyExpDateSelect';
 /*import DatePicker, { registerLocale } from 'react-datepicker';
 import { ja } from 'date-fns/locale/ja'; // date-fnsの日本語ロケールをインポート*/
 
@@ -89,73 +90,9 @@ const BuyDialog = ({
                         sx={{ marginBottom: 2 }}
                     />
 
-                    {/* 購入日・消費期限を横並びに */}
-                    <Box sx={{ display: 'flex', gap: 2, mb: 2 }}>
-                        {/* 購入日入力フィールド */}
-                        <TextField
-                            margin="dense"
-                            label="購入日"
-                            type="date"
-                            fullWidth
-                            value={newStock.buyDate ? newStock.buyDate.substring(0, 10) : ''}
-                            onChange={(e) =>
-                                setNewStock({ ...newStock, buyDate: e.target.value })
-                            }
-                            InputLabelProps={{ shrink: true }}
-                        />
-                        {/*<DatePicker
-                            popperClassName="custom-datepicker-popper"
-                            selected={newStock.buyDate ? new Date(newStock.buyDate) : null}
-                            onChange={(date) =>
-                                setNewStock({ ...newStock, buyDate: date ? formatDateLocal(date) : '' })
-                            }
-                            dateFormat="yyyy/MM/dd"
-                            customInput={
-                                <TextField
-                                    margin="dense"
-                                    label="購入日(yyyy/MM/dd)"
-                                    fullWidth
-                                />
-                            }
-                            isClearable
-                        //withPortal // ← 他の文字との重なり対策
-                        />*/}
+                    {/* 購入日・賞味期限入力 */}
+                    <BuyExpDateSelect newStock={newStock} setNewStock={({buyDate, expDate}) => setNewStock({...newStock, buyDate, expDate}) } />
 
-                        {/* 消費・賞味期限入力フィールド */}
-                        <TextField
-                            margin="dense"
-                            label="消費・賞味期限"
-                            type="date"
-                            fullWidth
-                            value={newStock.expDate ? newStock.expDate.substring(0, 10) : ''}
-                            onChange={(e) =>
-                                setNewStock({ ...newStock, expDate: e.target.value })
-                            }
-                            InputLabelProps={{ shrink: true }}
-                            InputProps={{
-                                inputProps: {
-                                    min: newStock.buyDate ? newStock.buyDate.substring(0, 10) : undefined,
-                                }
-                            }}
-                        />
-                        {/*<DatePicker
-                            popperClassName="custom-datepicker-popper"
-                            selected={newStock.expDate ? new Date(newStock.expDate) : null}
-                            onChange={(date) =>
-                                setNewStock({ ...newStock, expDate: date ? formatDateLocal(date) : '' })
-                            }
-                            dateFormat="yyyy/MM/dd"
-                            customInput={
-                                <TextField
-                                    margin="dense"
-                                    label="消費・賞味期限(yyyy/MM/dd)"
-                                    fullWidth
-                                />
-                            }
-                            isClearable
-                        //withPortal
-                        />*/}
-                    </Box>
                     {/* 購入店舗入力フィールド  */}
                     <TextField
                         margin="dense"
diff --git a/frontend/src/components/BuyExpDateSelect.tsx b/frontend/src/components/BuyExpDateSelect.tsx
new file mode 100644
index 0000000..9cf1a27
--- /dev/null
+++ b/frontend/src/components/BuyExpDateSelect.tsx
@@ -0,0 +1,80 @@
+import { Box, TextField } from "@mui/material"
+
+//  日付文字列（時間を含む可能性がある）から日付部分だけを返す
+const parseDate = ((date: string) => date ? date.substring(0, 10) : '')
+
+//  今日の日付
+const today = parseDate(new Date().toISOString());
+
+//  日付文字列で早いほうを返す（空でないものは除く）
+const validateBuyDate = ((buyDate: string) => {
+  // console.log('validateBuyDate:', buyDate)
+  if (!buyDate) { // 購入日が未設定の場合は今日の日付を入れておく
+    return today;
+  }
+  return parseDate(buyDate);
+})
+
+//  日付文字列で早いほうを返す（空でないものは除く）
+const validateExpDate = ((buyDate: string, expDate: string) => {
+  // console.log('validateExpDate:', buyDate, expDate)
+  if (!expDate) { // 賞味期限が未設定の場合そのまま未設定にする
+    return '';
+  }
+  const buyDateParsed = validateBuyDate(buyDate);
+  const expDateParsed = parseDate(expDate);
+  //  購入日以降となるようにする
+  return buyDateParsed > expDateParsed ? buyDateParsed : expDateParsed;
+})
+
+const BuyExpDateSelect = ({
+    newStock,
+    setNewStock,
+}: {
+    newStock: {buyDate: string, expDate: string},
+    setNewStock: (tobuy: {buyDate: string, expDate: string}) => void,
+}) => {
+
+  {/* 購入日・消費期限を横並びに */ }
+  return <Box sx={{ display: 'flex', gap: 2, mb: 2 }}>
+    {/* 購入日入力フィールド */}
+    <TextField
+      margin="dense"
+      label="購入日"
+      type="date"
+      fullWidth
+      value={validateBuyDate(newStock.buyDate)}
+      onChange={(e) =>
+        setNewStock({ ...newStock, buyDate: e.target.value })
+      }
+      InputLabelProps={{ shrink: true }}
+      InputProps={{
+        inputProps: {
+          max: today,
+        }
+      }}
+    />
+
+    {/* 消費・賞味期限入力フィールド */}
+    <TextField
+      margin="dense"
+      label="消費・賞味期限"
+      type="date"
+      fullWidth
+      value={validateExpDate(newStock.buyDate, newStock.expDate)}
+      onChange={(e) =>
+        setNewStock({ ...newStock, expDate: e.target.value })
+      }
+      InputLabelProps={{ shrink: true }}
+      InputProps={{
+        inputProps: {
+          min: validateBuyDate(newStock.buyDate),
+        }
+      }}
+    />
+   
+  </Box>
+
+}
+
+export default BuyExpDateSelect;
\ No newline at end of file
diff --git a/frontend/src/pages/StockPage.tsx b/frontend/src/pages/StockPage.tsx
index 899bce1..74bbf62 100644
--- a/frontend/src/pages/StockPage.tsx
+++ b/frontend/src/pages/StockPage.tsx
@@ -31,6 +31,7 @@ import { Add as AddIcon } from '@mui/icons-material';
 /*import DatePicker, { registerLocale } from 'react-datepicker';
 import { ja } from 'date-fns/locale/ja'; // date-fnsの日本語ロケールをインポート*/
 import { useMessage } from '../components/MessageContext';
+import BuyExpDateSelect from '../components/BuyExpDateSelect';
 
 /*// 日付をyyyy-MM-dd形式で返す関数
 const formatDateLocal = (date: Date) => {
@@ -479,79 +480,9 @@ const StockPage: React.FC = () => {
                   onChange={handleChange}
                 />
 
-                {/* 購入日・消費期限を横並びに */}
-                <Box sx={{ display: 'flex', gap: 2, mb: 2 }}>
-                  {/* 購入日 */}
-                  <TextField
-                    margin="normal"
-                    label="購入日"
-                    type="date"
-                    fullWidth
-                    name="buyDate"
-                    value={editStock.buyDate ? editStock.buyDate.substring(0, 10) : ''}
-                    onChange={(e) => setEditStock({ ...editStock, buyDate: e.target.value })}
-                    InputLabelProps={{ shrink: true }}
-                  />
-                  {/*<DatePicker
-                    selected={editStock.buyDate ? new Date(editStock.buyDate) : null}
-                    onChange={(date) => {
-                      if (editStock) {
-                        setEditStock({
-                          ...editStock,
-                          buyDate: date ? formatDateLocal(date) : '',
-                        });
-                      }
-                    }}
-                    dateFormat="yyyy/MM/dd"
-                    customInput={
-                      <TextField
-                        margin="normal"
-                        label="購入日 (yyyy/MM/dd)"
-                        fullWidth
-                        name="buyDate"
-                      />
-                    }
-                    isClearable
-                  />*/}
-                  {/* 消費・賞味期限 */}
-                  <TextField
-                    margin="normal"
-                    label="消費・賞味期限"
-                    type="date"
-                    fullWidth
-                    name="expDate"
-                    value={editStock.expDate ? editStock.expDate.substring(0, 10) : ''}
-                    onChange={(e) => setEditStock({ ...editStock, expDate: e.target.value })}
-                    InputLabelProps={{ shrink: true }}
-                    InputProps={{
-                      inputProps: {
-                        min: newStock.buyDate ? newStock.buyDate.substring(0, 10) : undefined,
-                      }
-                    }}
-                  />
-
-                  {/*<DatePicker
-                    selected={editStock.expDate ? new Date(editStock.expDate) : null}
-                    onChange={(date) => {
-                      if (editStock) {
-                        setEditStock({
-                          ...editStock,
-                          expDate: date ? formatDateLocal(date) : '',
-                        });
-                      }
-                    }}
-                    dateFormat="yyyy/MM/dd"
-                    customInput={
-                      <TextField
-                        margin="normal"
-                        label="消費・賞味期限 (yyyy/MM/dd)"
-                        fullWidth
-                        name="expDate"
-                      />
-                    }
-                    isClearable
-                  />*/}
-                </Box>
+                {/* 購入日・賞味期限入力 */}
+                <BuyExpDateSelect newStock={editStock} setNewStock={({ buyDate, expDate }) => setEditStock({ ...editStock, buyDate, expDate })} />
+
                 <Box sx={{ display: 'flex', justifyContent: 'flex-end', gap: 2, mt: 3, mb: 2 }}>
                   <Button onClick={() => { setIsEditOpen(false); setSelectedRow(null); }}>
                     キャンセル
@@ -767,74 +698,12 @@ const StockPage: React.FC = () => {
                 label="購入店舗"
                 fullWidth
                 value={newStock.shop}
-                onChange={(e) => setNewStock({...newStock, shop: e.target.value})}
+                onChange={(e) => setNewStock({ ...newStock, shop: e.target.value })}
               />
-              {/* 購入日・消費期限を横並びに */}
-              <Box sx={{ display: 'flex', gap: 2, mb: 2 }}>
-                {/* 購入日入力フィールド */}
-                <TextField
-                  margin="dense"
-                  label="購入日"
-                  type="date"
-                  fullWidth
-                  value={newStock.buyDate ? newStock.buyDate.substring(0, 10) : ''}
-                  onChange={(e) =>
-                    setNewStock({ ...newStock, buyDate: e.target.value })
-                  }
-                  InputLabelProps={{ shrink: true }}
-                />
-                {/*<DatePicker
-                  popperClassName="custom-datepicker-popper"
-                  selected={newStock.buyDate ? new Date(newStock.buyDate) : null}
-                  onChange={(date) =>
-                    setNewStock({ ...newStock, buyDate: date ? formatDateLocal(date) : '' })
-                  }
-                  dateFormat="yyyy/MM/dd"
-                  customInput={
-                    <TextField
-                      margin="dense"
-                      label="購入日(yyyy/MM/dd)"
-                      fullWidth
-                    />
-                  }
-                  isClearable
-                //withPortal // ← 他の文字との重なり対策
-                />*/}
-                {/* 消費・賞味期限入力フィールド */}
-                <TextField
-                  margin="dense"
-                  label="消費・賞味期限"
-                  type="date"
-                  fullWidth
-                  value={newStock.expDate ? newStock.expDate.substring(0, 10) : ''}
-                  onChange={(e) =>
-                    setNewStock({ ...newStock, expDate: e.target.value })
-                  }
-                  InputLabelProps={{ shrink: true }}
-                  InputProps={{
-                    inputProps: {
-                      min: newStock.buyDate ? newStock.buyDate.substring(0, 10) : undefined,
-                    }
-                  }}
-                />
-                {/*<DatePicker
-                  popperClassName="custom-datepicker-popper"
-                  selected={newStock.expDate ? new Date(newStock.expDate) : null}
-                  onChange={(date) =>
-                    setNewStock({ ...newStock, expDate: date ? formatDateLocal(date) : '' })
-                  }
-                  dateFormat="yyyy/MM/dd"
-                  customInput={
-                    <TextField
-                      margin="dense"
-                      label="消費・賞味期限(yyyy/MM/dd)"
-                      fullWidth
-                    />
-                  }
-                  isClearable
-                //withPortal
-                />*/}
-              </Box>
+
+              {/* 購入日・賞味期限入力 */}
+              <BuyExpDateSelect newStock={newStock} setNewStock={({ buyDate, expDate }) => setNewStock({ ...newStock, buyDate, expDate })} />
+
             </Box>
           </DialogContent>
           <DialogActions>
diff --git a/frontend/src/pages/TaskListPage.tsx b/frontend/src/pages/TaskListPage.tsx
index 51a7f06..bc5b43a 100644
--- a/frontend/src/pages/TaskListPage.tsx
+++ b/frontend/src/pages/TaskListPage.tsx
@@ -69,8 +69,8 @@ const TaskListPage: React.FC = () => {
     amount: '', // 購入数量(ここではstring)
     price: '', // ここではstring
     shop: '',
-    buyDate: new Date().toISOString(),
-    expDate: '',
+    buyDate: '', // 日付選択側で今日の日付がデフォルトで選択されている
+    expDate: '', // 未設定状態
   });
 
   //削除確認ダイアログの表示状態