To prevent deterioration of an appearance caused, for example, on account of a conspicuous corner in a gluteal cover portion.The above problem is solved by the following. That is, three or more elongated cover portion elastic members 16a to 16c along a width direction WD are disposed in a gluteal cover portion C of a back outer member 12B at intervals in a front-back direction LD. The gluteal cover portion C is contracted toward the center in the width direction by the cover portion elastic members 16a to 16c. The cover portion elastic member 16a located closest to a waist opening WO is disposed at an end portion of the gluteal cover portion C on the waist opening WO side, and the cover portion elastic member 16c located closest to a leg opening LO is disposed at an end portion of the gluteal cover portion C on the leg opening LO side. When a central interval between the cover portion elastic member 16a located closest to the waist opening WO and the cover portion elastic member 16b located second from the waist opening WO is represented by dA, and the front-back direction length of the gluteal cover portion C is represented by dE, dA >； 0.5dE is satisfied.
