A plurality of elastic members (81, 82) extending in a width direction (X) are arranged on an enveloping member (6) on a ventral section (A) and a dorsal section (B), there being a pair of side seal sections (7) formed by mutually overlapping and joining together bilateral edges (6a) of the ventral section (A) and bilateral edges (6b) of the dorsal section (B). The side seal sections (7) are formed by intermittent ultrasonic bonding of the bilateral edges (6a, 6b) along the longitudinal direction (Y). The elastic members (81, 82) are fixed to an outer sheet (61) and an inner sheet (62) of the enveloping member (6) using only an adhesive agent (9) between the sheets. The adhesive agent (9) fixes the elastic members (81, 82) at two end areas of the elastic members (81, 82). A region to which the adhesive agent (9) is applied is located further inward than the side edges of the side seal sections (7) outward in the width direction.
