PROBLEM TO BE SOLVED: To surely fasten upper and lower elastic sheets to parts to be fastened respectively on the cross and sufficiently keep the strength of a fastening tape.SOLUTION: A disposable diaper 1 is provided with the body part 10 comprising a ventral part 11 and a dorsal part 12. The diaper 1 includes: a pair of upper and lower two steps of elastic sheets 20, 30 which are prepared extendedly in both side directions of the dorsal part 12, which have expandable/contractible elastic parts 23, 33, and which have fastening members 22, 32 fixed to the free ends 21, 31 in both directions and a part to be fastened 40 which is provided on the outer face of the side opposite from the face in contact with the human body of the ventral part 11, and which are freely attachably/detachably fastened with the fastening members 22, 32. At least one of the upper and lower two steps of elastic sheets 20, 30 is provided with perforations 34 that can produce an opening 35 and with elastic parts 33a, 33b that are on the proximal end side and the free end side from the part provided with the perforations 34.
