[PROBLEMS] A trunks type disposable diaper and a method of efficiently producing the diaper. [MEANS FOR SOLVING PROBLEMS] In the pants type disposable diaper, opposite side edges and a recessed edge of each of front and rear body sections are joined to each other. This creates crotch tube sections that each have a leg opening at their ends and are each formed by the lower portion of the joint between each of the opposite side edges and by the joint between the recessed edges.