A method including: a step of carrying first and second continuous webs in a predetermined carrying direction; a first slitting step of slitting the first continuous web along a virtual first cut-off line extending the carrying direction, thereby dividing the first continuous web into a wider first divided web and a narrower second divided web; a step of sandwiching an around-torso elastic member extending in a girth direction between the wider first divided web and the second continuous web; a welding step of welding together the first divided web, the second continuous web and the around-torso elastic member intermittently in the carrying direction, thereby producing a layered sheet; and a bonding step of sandwiching an around-leg elastic member meandering relative to the carrying direction between the layered sheet and the narrower second divided web, and attaching the around-leg elastic member thereto by an adhesive, thereby producing a stretchable continuous sheet.