PROBLEM TO BE SOLVED: To prevent direct contact of the lower edge of a fastening tape in a tape type disposable diaper with the skin of a user, and to prevent impairment of a sense of wearing and injury to the skin.SOLUTION: At least a waist side flap WF of an abdominal side part F is formed by joining an external sheet 12 with inner side layers 11 and 62. An unjoined part 15 extending in the lateral direction is formed in an intermediate part in the vertical direction of the waist side flap. When a disposable diaper is worn, the external sheet 12 is made to project from the inner side layers 11 and 62 in the unjoined part 15 to form a pleated part 16, and the lower edge of a fastening tape 13 can be located on the upper side of the pleated part 16.
