A chassis of a diaper includes a first outer sheet defining a front waist region and a part of a crotch region, a second outer sheet defining a rear waist region and a part of the crotch region and a middle sheet connecting these sheets and defining a part of the crotch region. To the skin-facing side of the chassis, a liquid-absorbent structure is attached. The liquid-absorbent structure is provided with first and second elastic sheets overlapping front and rear ends of the liquid-absorbent structure, respectively. The first elastic sheet is attached under tension in a transverse direction and in contractible manner between a bottom surface of the liquid-absorbent structure and the first outer sheet and the second elastic sheet is located on a skin-facing surface of the liquid-absorbent structure and attached thereto under tension in the transverse direction and in contractible manner.