A stretchable sheet 10 includes: a plurality of attached portions 3 spaced apart from each other in the direction of stretch Df, wherein the first surfaces 1f and 2f of a pair of sheets 1 and 2 are attached to each other by being welded without using an adhesive, at the attached portions 3, the attached portions 3 hold elastic members F, and the attached portions 3 extend in a direction Dp crossing the direction of stretch Df of the elastic members F; and a plurality of folds P that appear between the attached portions 3 while 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 elastic member F in the crossing direction Dp; and a plurality of weakly-attached portions 3w arranged between adjacent elastic members F and between adjacent strongly-attached portions 3s.