To provide a diaper which can be worn according to a size difference of a body of an infant (premature infant and low birth weight infant) and which can suppress interference to cure and nursing care.SOLUTION: A diaper 2 comprises: a nonwoven fabric 3 extending from a back side of an infant and toward an abdominal side through a crotch part； a back sheet 4 for suppressing transmission of excrement discharged by an infant； an absorber 5 provided between the nonwoven fabric 3 and the back sheet 4 and absorbs the excrement transmitted the nonwoven fabric 3； and a belt part 6 which has connection parts 63 connected to the nonwoven fabric 3 in a detachable state. At least a part of a part where the nonwoven fabric 3 and the back sheet 4 are laminated, does not overlap to the absorber 5 and serves as an extension part 31 extending from an abdominal end part of the absorber 5 to an abdominal side. In a direction of extension of the nonwoven fabric 3, a length L1 of the extension part 31 is longer than a length L2 of the connection part 63.SELECTED DRAWING: Figure 1【課題】乳幼児（未熟児や低出生体重児）の体の大きさの違いに対応して装着可能とされ、治療や看護の妨げになることを抑えることができるおむつを提供すること。【解決手段】おむつ２は、乳幼児の背側から股間部を通り腹側にわたって延びる不織布３と、乳幼児が排出した排泄物の透過を抑えるバックシート４と、不織布３とバックシート４との間に設けられ不織布３を透過した排泄物を吸収する吸収体５と、不織布３に対して着脱自在に連結可能な連結部６３を有するベルト部６と、を備える。不織布３とバックシート４とが互いに張り合わされた部分の少なくとも一部は、吸収体５とは重ならず、吸収体５の腹側の端部から更に腹側に向かって延びた延設部３１となっている。不織布３が延びた方向において、延設部３１の長さＬ１は、連結部６３の長さＬ２よりも長い。【選択図】図１
