The present invention provides a disposable diaper, which is easy to put on the wearer, and which is possible to be put on easily while the wearer is standing on both legs. The disposable diaper according to the present invention includes a diaper body having a hip portion and a belly portion, which are spread out with a crotch portion between them. The diaper further includes male members which are protrusively arranged from side portions of one of the hip portion and said belly portion in a face direction and female members, which are arranged on side portions of the other and in which the male members engage in a face direction of the side portions. The female members are provided with receiving portions in which the male members are inserted in a face direction of the side portions. Engaged surfaces perpendicular to the inserting direction of the male member are formed on the inner walls of the receiving portions and the male members are provided with engaging surfaces opposing to the engaged surfaces.