A disposable diaper (1) which comprises a fastening member (3) provided with a closing portion (31) on both side portions of a rear side portion (A) of a diaper main body (2). The fastening member (3) has: a base end portion (32) which is fixed to the diaper main body (2) an elastic wide portion (33) which is housed inside a housing portion (5) that is formed in the diaper main body and a holding portion (37) the length of which is shorter than the elastic wide portion (33) in the longitudinal direction (X) of the diaper. The elastic wide portion (33) can be stretched inside the housing portion (5) in the width direction (Y) of the diaper. The holding portion (37) has the closing portion (31) on a part thereof which extends out from the housing portion (5). The housing portion (5) has a fastening member outlet (52) on the edge of the outer side in the width direction of the diaper, the fastening member outlet (52) having a length in the longitudinal direction of the diaper that is shorter than the elastic wide portion (33). The holding portion (37) is inserted through the fastening member outlet (52).
