Between the first non-woven fabric 30mf1 continuous in the transport direction and the second non-woven fabric 30mf2 continuous in the transport direction while being overlapped with the first non-woven fabric 30mf1 in the thickness direction, along the transport direction A plurality of elastic members 35a, 35a... Are arranged in the CD direction intersecting the conveyance direction, and a step of conveying the composite sheet 30mf fixed by being interposed, elastic members 35a adjacent in the CD direction in the composite sheet 30mf , 35a by pushing the pushing member 55p in the thickness direction to form a through hole h in the composite sheet 30mf, and a through hole forming processing position P51 in which the through hole h is formed in the same step S50. Step S60 of applying tension in the CD direction to the composite sheet 30 mf at a position downstream of the sheet and tension applied with the tension in the step S60 At a position downstream in the transport direction from the position P60, with a step S70 to perform processing for the composite sheet 30 mF, the.搬送方向に連続する第１不織布３０ｍｆ１と、厚さ方向に第１不織布３０ｍｆ１に重なって配されつつ搬送方向に連続する第２不織布３０ｍｆ２との間に、搬送方向に伸長状態で搬送方向に沿った複数の弾性部材３５ａ，３５ａ…が、搬送方向と交差するＣＤ方向に並んだ状態で介挿されて固定された複合シート３０ｍｆを搬送する工程と、複合シート３０ｍｆにおいてＣＤ方向に隣り合う弾性部材３５ａ，３５ａ同士の間の位置に厚さ方向に押し込み部材５５ｐを押し込むことで、複合シート３０ｍｆに貫通孔ｈを形成する工程Ｓ５０と、同工程Ｓ５０で貫通孔ｈを形成する貫通孔形成処理位置Ｐ５１よりも下流側の位置において、複合シート３０ｍｆにＣＤ方向の張力を付与する工程Ｓ６０と、同工程Ｓ６０で上記張力を付与する張力付与位置Ｐ６０よりも搬送方向の下流側の位置において、複合シート３０ｍｆに加工を行う工程Ｓ７０と、を有する。
