Fitting to male genitalia is improved. The above-mentioned problem is solved by that at least a male-genitalia-facing portion (100) and portions on both sides thereof in a width direction (WD), in an outer member (20) of a front body (F), have an elastic film stretchable structure (20X) in which an elastic film (30) is stacked between a first sheet layer (20A) and a second sheet layer (20B) and the first sheet layer (20A) and the second sheet layer (20B) are bonded directly or indirectly by a large number of sheet bonded portions (40) arranged at intervals; a change region (90) in which an area rate of the bonded portions (40) decreases stepwise or continuously from a central portion of the male-genitalia-facing portion (100) in a width direction (WD) to the portions of the both sides of the male-genitalia-facing portion (100) in the width direction (WD), is included; and at least a portion of the change region (90) other than a portion having the highest area rate of the bonded portions (40), is contracted in the width direction (WD) due to contraction of the elastic film (30) in a natural length state and is extensible in the width direction (WD) .