The present invention aims to provide a disposable pull-on diaper improved so that the diaper may be conveniently put on the wearer's body.Each of leg side flaps of a crotch panel has an outer side region and an inner side region. In the lowest region of the crotch region, the outer side region and the inner side region respectively have a dimension of at least 10 mm in a transverse direction wherein the inner side region extends in a longitudinal direction and the outer side region extends in the transverse direction from the inner side region.