PROBLEM TO BE SOLVED: To provide a diaper hardly generating creases on a base material sheet between upper and lower two-stage projection parts, when being cross-fixed.SOLUTION: In a disposable diaper, a fastening base material sheet projecting outward is provided on both sides on the back side of the diaper, at least upper and lower two-stage projection parts projecting furthermore outward than the base material sheet are formed, and an adhesive layer or fastening means including a hook-and-loop fastener element is provided on the inner surface of the projection parts, to thereby fasten the base material sheet onto the external surface on the abdominal side of the diaper through the fastening means. Further, a folding line is formed from the tip side toward the base end side of the base material sheet between the upper and lower projection parts.
