An unfolding type disposable diaper (1) for an infant having a body weight of 3000 g or less having a longitudinal direction a width direction and a thickness direction orthogonal to each other and being provided with a front waist surrounding area (1a) a crotch area (1b) and a rear waist surrounding area (1c) the unfolding type disposable diaper (1) having an absorbent body (4) a pair of fastening members (10) extending outward in the width direction from the rear waist surrounding area (1c) leg surrounding stretchable members (6) provided along a pair of leg surrounding openings (HL) formed by fastening of the pair of fastening members (10) to the front waist surrounding area (1a) and provided further outside in the width direction than the absorbent body (4) and a target display part (15) for indicating the position at which to fasten the pair of fastening members (10) to the front waist surrounding area (1a) the absorbent body (4) being provided with an overlap region (A) in the longitudinal direction which overlaps with the target display part (15) in the thickness direction and the length (L1) of the target display part (15) in the width direction being equal to or less than the maximum length (L2) of the absorbent body (4) in the width direction in the overlap region (A).
