PROBLEM TO BE SOLVED: To prevent a reduction in fitting properties at end parts of a waist or the like while an abdominal side exterior body and a back side exterior body have a simple structure without a folding of a sheet material.SOLUTION: In an underpants type disposable diaper, a contracting belt 12 continuing in the form of a belt is formed by sandwiching elastic expanding and contracting members 15 to 19 between a first sheet material 12S and a second sheet material 12H and joining a region where the first sheet material 12S and the second sheet material 12H are overlapped not at both end parts in a CD direction but in a region between them. A pair of divided expanding and contracting belts 12f, 12b is formed by cutting the expanding and contracting belt 12 between the elastic expanding and contracting members 15 to 19 in the middle in the CD direction and at joining positions of the first sheet material 12S and the second sheet material 12H. The positions of the divided expanding and contracting belts 12f, 12b are interchanged with each other in the CD direction, or the divided expanding and contracting belts 12f, 12b are vertically inverted, respectively. An abdominal side exterior body 12F and a back side exterior body 12B are formed by the pair of the divided expanding and contracting belts 12f, 12b.【課題】腹側外装体及び背側外装体をシート材の折り返しの無い簡素な構造としつつ、ウエストの端部のフィット性の低下等を防止する。【解決手段】上記課題は、第１シート材１２Ｓ及び第２シート材１２Ｈ間に弾性伸縮部材１５～１９が挟まれるとともに、第１シート材１２Ｓ及び第２シート材１２Ｈの重なる領域がＣＤ方向両端部では接合されず、それらの間の領域で接合されることにより、帯状に連続する伸縮帯１２が形成され、この伸縮帯１２が、そのＣＤ方向中間における弾性伸縮部材１５～１９の間かつ第１シート材１２Ｓ及び第２シート材１２Ｈの接合位置で切断されて一対の分割伸縮帯１２ｆ，１２ｂが形成され、これら分割伸縮帯１２ｆ，１２ｂのＣＤ方向位置が入れ替えられるか、又はこれら分割伸縮帯１２ｆ，１２ｂがそれぞれ上下反転され、これら一対の分割伸縮帯１２ｆ，１２ｂにより腹側外装体１２Ｆ及び背側外装体１２Ｂが形成されることで解決される。【選択図】図１
