The present invention on its first aspect provides a disposable diaper improved so as to prevent body waste from leaking sideways without sacrificing a bodily fluid absorbing capacity of a liquid-absorbent structure and to assure appropriate fitness to the wearers body. In each of front and rear waist regions 13, 14, a disposable diaper 10 comprises an upper elasticized region 18 extending in a vicinity of a waist-opening periphery 16a, lower elasticized regions 20A, 20B, intermediate elasticized region 19 extending between the upper elasticized region 18 and the lower elasticized regions 20A, 20B and outside longitudinally opposite ends 12a, 12b of a liquid-absorbent structure 12, and, at least in the front waist region 13 of the front and rear waist regions 13, 14, a non-elasticized region 30 opposed to a central zone of a liquid-absorbent core wherein a tensile stress of the intermediate elasticized region 19 is lower than a tensile stress of the upper elasticized region 18.第1發明提供一種,不會降低體液吸收性能,防止排泄物的側漏的同時,具有對穿用者身體的適度的貼合性的用後即棄式紙尿褲。又,第2發明提供一種,不會降低體液吸收性能,可防止體液的側漏的同時,具有顯著尿便保持性的用後即棄式紙尿褲。解決手段,用後即棄式紙尿褲(210),其腰部彈性構件是由:在腰開口(216)的附近,往橫向延伸的第1腰部彈性構件(231)、與位在腿開口緣(217)與第1腰部彈性構件(231)之間,在前後腰域(213、214)的兩側部,往橫向延伸,且沒有延伸於前後腰域(213、214)的中央域之第2腰部彈性構件(232)所構成,前腰域(213)的第2腰部彈性構件(232)在吸液性芯(244)的側緣從前腰域(213)的側緣越過其內側往橫向延伸,後腰域(214)的第2腰部彈性構件(232),從後腰域(214)的側緣沒有與吸液性芯(244)的側緣交叉地往吸液性芯(244)的側緣的附近延伸。225‧‧‧後腰域的側緣部224‧‧‧前腰域的側緣部218‧‧‧上側彈性域219‧‧‧下側彈性域219A、219B‧‧‧下側彈性域220‧‧‧前後腰域的兩側部213‧‧‧前腰域212‧‧‧吸液性構造體230‧‧‧非伸縮域234‧‧‧摺邊231‧‧‧第1腰部彈性構件214‧‧‧後腰域232‧‧‧第2腰部彈性構件211‧‧‧主體215‧‧‧胯下域233‧‧‧腿部彈性構件216‧‧‧腰開口210‧‧‧用後即棄式紙尿褲216a‧‧‧腰部開緣226‧‧‧接縫部233‧‧‧腿部彈性構件217‧‧‧腿開口
