A stretchable sheet comprising: a pair of sheets 1 and 2 whose first surfaces 1f and 2f oppose each other or are in contact with each other; a plurality of elastic members F that are arranged between the first surfaces 1f and 2f of the pair of sheets 1 and 2 and are arranged spaced apart from each other; a plurality of attached portions 3, wherein the first surfaces 1f and 2f of the pair of sheets 1 and 2 are attached to each other by a welding construction without using an adhesive, at the attached portions 3; the attached portions 3 hold the elastic members F; the attached portions 3 extend in a direction Dp crossing a direction of stretch Df of the elastic members F; and the attached portions 3 are spaced apart from each other in the direction of stretch Df between adjacent elastic members F of the elastic members F; and a plurality of folds P that appear between the attached portions 3 in a state where the elastic members F are shrunk, wherein the attached portions 3 include: a plurality of strongly-attached portions 3s arranged on opposite sides of each of the elastic members F in the crossing direction Dp; and a plurality of weakly-attached portions 3w; each of the weakly-attached portions 3w being arranged between adjacent elastic members F of the elastic members F and between adjacent strongly-attached portions 3s of the strongly-attached portions 3s, wherein a strength of attachment between the pair of sheets 1 and 2 at the weakly-attached portions 3w is less than a strength of attachment between the pair of sheets 1 and 2 at the strongly-attached portions 3s. a pair of sheets 1 and 2 whose first surfaces 1f and 2f oppose each other or are in contact with each other; a plurality of elastic members F that are arranged between the first surfaces 1f and 2f of the pair of sheets 1 and 2 and are arranged spaced apart from each other; a plurality of attached portions 3, wherein the first surfaces 1f and 2f of the pair of sheets 1 and 2 are attached to each other by a welding construction without using an adhesive, at the attached portions 3; the attached portions 3 hold the elastic members F; the attached portions 3 extend in a direction Dp crossing a direction of stretch Df of the elastic members F; and the attached portions 3 are spaced apart from each other in the direction of stretch Df between adjacent elastic members F of the elastic members F; and a plurality of folds P that appear between the attached portions 3 in a state where the elastic members F are shrunk, wherein the attached portions 3 include: a plurality of strongly-attached portions 3s arranged on opposite sides of each of the elastic members F in the crossing direction Dp; and a plurality of weakly-attached portions 3w; each of the weakly-attached portions 3w being arranged between adjacent elastic members F of the elastic members F and between adjacent strongly-attached portions 3s of the strongly-attached portions 3s, wherein a strength of attachment between the pair of sheets 1 and 2 at the weakly-attached portions 3w is less than a strength of attachment between the pair of sheets 1 and 2 at the strongly-attached portions 3s. a plurality of strongly-attached portions 3s arranged on opposite sides of each of the elastic members F in the crossing direction Dp; and a plurality of weakly-attached portions 3w; each of the weakly-attached portions 3w being arranged between adjacent elastic members F of the elastic members F and between adjacent strongly-attached portions 3s of the strongly-attached portions 3s, wherein a strength of attachment between the pair of sheets 1 and 2 at the weakly-attached portions 3w is less than a strength of attachment between the pair of sheets 1 and 2 at the strongly-attached portions 3s.