To prevent wrinkling of both side portions and collapsing of holes when a perforated nonwoven fabric is used for a cover nonwoven fabric in an outer member separated-type underpants-type disposable diaper. To solve the above problem, a cover nonwoven fabric 13 covering a back surface of an inner member 200 from between a front side outer member 12F and the inner member 200 to between a back side outer member 12B and the inner member 200 is included, the cover nonwoven fabric 13 extends at least from a back surface side of a base portion of one side gather 60 to a back surface side of a base portion of the other side gather 60. The cover nonwoven fabric 13 is provided with a large number of holes 14 penetrating the front surface and back surface at intervals from between the front side outer member 12F and the inner member 200 to between the back side outer member 12B and the inner member 200. The side edges of the cover nonwoven fabric 13 are located at the positions same as the side edges of the narrowest part of the absorber 56 in the width direction or located at positions on the center side in the width direction with respect to the side edges of the narrowest part.
