To provide a disposable diaper in which a barrier cuff can be securely developed from a stored-status to a developed-status.

This disposable diaper includes a liquid permeable first layer 86, a chassis layer 840, an absorption core 84 between the first layer and the chassis layer, and the barrier cuff 810. The inner surface of the cuff is adhered to the first layer at the end section in the longitudinal direction of the cuff in which a part from which a proximal end section 895 runs in the lateral direction is inwardly adhered to the first layer. Next, a distal end section 812 having an elastic space member 94 is folded to the outside in the lateral direction toward the proximal end section, thereby providing the above end section in the longitudinal direction with a first segment 820 and a second segment 822. At this end section in the longitudinal direction, the outer surfaces of the cuff at the first segment and the second segment are adhered to each other. The proximal end section at a crotch section is adhered to the outer side from the side edge section in the lateral direction of the absorption core. The cuff at the crotch section stands up so as to substantially run away from the first layer in a straight manner.