Disclosed is a manufacturing method for an underpants-type diaper (1) which is provided with: an external body (2) which is provided with a separate front body (4) and back body (5), and a connecting sheet (6), said front body (4) and back body (5) being joined together at the sides, and connected together by the connecting sheet along an anterioposterior direction in the crotch area an internal body (3) which is layered and fixed on the connecting sheet (6) in the external body, and which includes an absorbent main body. A front body substrate which is a continuous form of the front body, and a back body substrate which is a continuous form of the back body are conveyed along a conveyance direction having a separated area in the direction perpendicular to the conveyance direction. Next, the connecting sheet is mounted to the front substrate and the back substrate so as to cross the spaced area leaving spaces in the conveyance direction, forming the external body substrate which is the continuous form of the external body. Next, the external body substrate is cut to form lines which define leg holes. Next, the internal body is mounted to the external body substrate.
