A standing elastic filament (9) and a leg-use elastic filament (10) are respectively attached in a preset relation to each of side sheets (4) provid ed on the opposite sides of a skin-side sheet (3), and each side sheet (4) is bonded to the skin-side sheet (3) in a preset relation to thereby form a standing gather and a leg-use gather on each side sheet (4) at the same time ; and a pocket (12) into which a replaceable, generally sandglass-shaped secon d absorber (11) is inserted by positioning is formed in a space surrounded by respective bonded portions between the ski-side sheet (3) and respective sid e sheets (4).
