A disposable diaper having a liquid pervious topsheet, a liquid impervious and vapor pervious backsheet and an absorbent core interposed between the topsheet and the backsheet comprises interposing a liquid impervious and vapor pervious barrier sheets between the topsheet and the backsheet, said barrier sheets being extended from the front edge and the rear edge of the diaper to the inwards of the front edge and the rear edge of the absorbent core respectively, to thereby form waist barrier parts covering the front edge and the rear edge of the absorbent core, and said barrier sheets being so formed that the intensity in the lateral direction of the diaper is higher than the intensity in the longitudinal direction of the diaper.