A disposable diaper (1) for children with body weights of 3000 g or less, the disposable diaper comprising: side flaps (14) a pair of fastening tapes (30) provided on the side flaps (14) and a target region (29) capable of fastening to the fastening tapes (30). The pair of fastening tapes (30) can be fastened by overlaying one of the fastening tapes (30) on the other fastening tape (30). If the fastening force between the target region (29) and one of the fastening tapes (30) is P1 and the fastening force between the one fastening tape (30) and the other fastening tape (30) is P2, the relationship P1 > P2 > 0.1 N/10 mm holds. When the paired fastening tapes (30) are overlaid with the centers of the fastening tapes (30) in the tape width direction aligned, the upper fastening tape (30) can fasten to the target region (29) at the two sides that straddle the end of the lower fastening tape (30) in the tape width direction.
