Hideyuki Nakamura, Osaka (JP); and Miwa Koshijima, Osaka, Japan.
Assigned to Zuiko Corporation, Osaka, Japan.

Filed: 9/7/17
Issued: 9/1/20

A stretchable sheet comprising: a pair of sheets whose first surfaces oppose each other or are in contact with each other; a plurality of elastic members that are arranged between the first surfaces of the pair of sheets and are arranged spaced apart from each other; a plurality of attached portions, wherein the first surfaces of the pair of sheets are attached to each other by a welding construction without using an adhesive, at the attached portions; the attached portions hold the elastic members; the attached portions extend in a direction crossing a direction of stretch of the elastic members; and the attached portions are spaced apart from each other in the direction of stretch at positions where the attached portions cross the elastic members; and a plurality of folds that appear between the attached portions in a state where the elastic members are shrunk, wherein a width of the attached portions in the direction of stretch is set to be 0.2 mm or more and less than 1.0 mm, the folds are formed as the pair of sheets protrude, between the attached portions, with respect to a virtual plane that includes the elastic members; and in an area defined between adjacent attached portions of the attached portions and adjacent elastic members of the elastic members, non-bonded positions of the pair of sheets that oppose each other protrude in the same direction, thereby forming a fold of the folds.