In the present invention, one surface of a band-shaped sheet laminate body (10) (a diaper continuous body) in which a plurality of sheets are stacked, is contacted with a support member (21), which includes an through hole (21H), so as to overlap the through hole (21H), and a fusing tool (27) introduced from the through hole (21H) is pushed against the band-shaped sheet laminate body (10), when the same is in a pressured state, to simultaneously segmentalize the band-shaped sheet laminate body (10) and fuse the cut edges, which are created by the segmentation, of the pressured plurality of sheets together to form sealing edges (4) (side sealing parts), in which the edges the plurality of sheets are fused in the overlapped state.
