Fasteners folded in two are arranged on one main surface of a first continuous body so that ends of the fasteners are arranged on the outside of the one main surface. A second continuous body is laid over another main surface of the first continuous body in a state where one end is bent so as to be laid over the other main surface, and the first continuous body and second continuous body are bonded together to form a composite continuous body to which the one end of the fasteners is fixed. The composite continuous body is cut to form a piece on which the pair of fasteners is arranged only in a first region. The piece is folded in two along an imaginary line and overlapped, and then the other end of the fasteners is bent and laid over and fixed to a second region.