The adhesion of a built-in body and the ventral or dorsal external sheet by deformation of the absorbent core peeled away or to prevent deterioration of the appearance or a sense of mounting. At the same time as the front end of the internal body 20 connected to a widthwise center part the inner surface of the stomach external sheet (12F), coupled to the width direction center part the inner surface of the rear end of the dorsal external sheet (12B), ventral external sheet (12F) and the dorsal external sheet (12B), the length of the portion is overlapped with the length of the pull-on type disposable diaper are not continuous in the crotch side, the absorbent core front end (56F) L1, the absorbent core 56 and the ventral external sheet (12F) L2, absorption L3, absorption length after the core end portion (56B), the core 56 and the dorsal external sheet (12B) tightening the length of the overlapped portion of L4, with (56N), the width W1, the absorbent core front end portion width and the absorbent core of when the rear end portion in the width W2, 90 mm≤W1
