PROBLEM TO BE SOLVED: To provide an open type disposable diaper being easily attachable/detachable with respect to a wearer in a standing position and stably locking a front waist area during attaching operation and during wearing.SOLUTION: At least one belt part 26 of an elastic waist belt 16 includes: a first elastic area 41 extending from side edges 15c and 15d of a liquid-absorbing structure 15 outward in the lateral direction X； a second elastic area 42 separately facing the first elastic area 41 in the lateral direction； and a non-elastic area 40 located between the first and second elastic areas. Second fastening means 18 comprises a first locking part 74 located in a skin facing surface of a front end 51 of an absorbing chassis 15, and a second locking part 75 located at a skin non-facing surface of the nonelastic area.【課題】立位状態の着用者に対して容易に着脱操作をすることができ、かつ、着用操作中及び着用中において前ウエスト域が安定的に止着される開放型の使い捨ておむつの提供。【解決手段】弾性ウエストベルト１６のうちの少なくとも一方のベルト部２６は、吸液構造体１５の側縁１５ｃ，１５ｄから横方向Ｘの外側に延びる第１弾性域４１と、第１弾性域４１と横方向において離間対向する第２弾性域４２と、第１及び第２弾性域間に位置する非弾性域４０とを有する。第２ファスニング手段１８は、吸収シャーシ１５の前端部５１の肌対向面側に位置する第１止着部７４と、非弾性域の非肌対向面側に位置する第２止着部７５とから構成される。【選択図】図２
