A body fluid absorbing component of a pull-on disposable diaper is folded inward in a crotch covering region. Outside opposite side edges of the absorbing component, there are provided a pair of barrier walls extending in a longitudinal direction of the absorbing component. The barrier wall is provided along its zone opposed to an outer surface of the absorbing component, a distal edge of the barrier wall and an intermediate zone defined between the zone and the distal edge with first, second and third elastic members, respectively, each extending in a stretched state in the longitudinal direction of the absorbing component.