Provided is a disposable diaper, in which fastening tapes are brought into direct engagement with the surface of an outer-face back sheet made of a nonwoven fabric. The disposable diaper is enabled to adjust its size slightly according to the body shape of a baby, by improving the force of the fastening tapes to engage with the outer-face back sheet and the force to join the outer-face back sheet and a leakage-preventing sheet.The disposable diaper has its outer-face back sheet made of a nonwoven fabric prepared by an air-through method, in which fibers are thermally melted to each other at the time of manufacturing the nonwoven fabric by feeding hot air in a drum transfer process. This nonwoven fabric is arranged to have the aforementioned drum contacting face side on the inner face side of the diaper and the drum noncontact face side on the outer face side of the diaper, or the outer face side of the aforementioned outer-face back sheet is subjected to a raising treatment over a predetermined rangeset as at least the engaging range of the aforementioned fastening tapes. As a result, the engaging force of the fastening tapes can be improved, and at least the aforementioned front-side end flap portion EFF can be longitudinally folded back at an arbitrary position.
