To provide a disposable diaper in which fitting property on appearance is hardly deteriorated even when an absorbent core is deformed.SOLUTION: A diaper 1 comprises a front face sheet 2, a rear face sheet 3 and an absorber 4 between the sheets 2, 3. The absorber 4 includes an absorbent core 40, the absorbent core 40 comprises on a crotch part C, a center bending guide part 43 formed of a low fiber lamination part and extends in a longitudinal direction X, and a pair of side part bending guide parts 44 each of which is formed of a low fiber lamination part and provided on one of both sides of the center bending guide part 43, and extends in the longitudinal direction X. The rear face sheet 3 is jointed to a covering sheet for covering a non-skin facing surface of the absorbent core 40 at a pair of inside junctions 13 each of which is provided between the center bending guide part 43 and one of the pair of side part bending guide parts 44, and extends in the longitudinal direction X, and a pair of outside junctions 14, 14 each of which is provided outside of the pair of side part bending guide parts 44 in a width direction Y and extends in the longitudinal direction X.SELECTED DRAWING: Figure 3【課題】吸収性コアが変形しても、外観上のフィット性が損なわれ難い、使い捨ておむつを提供すること。【解決手段】おむつ１は、表面シート２、裏面シート３、及びこれら両シート２，３間に介在された吸収体４を備えている。吸収体４は、吸収性コア４０を含んでおり、該吸収性コア４０は、股下部Ｃに、低積繊部からなり、長手方向Ｘに延びる中央折曲誘導部４３と、低積繊部からなり、該中央折曲誘導部４３の両側それぞれに位置し、長手方向Ｘに延びる一対の側部折曲誘導部４４とを有している。裏面シート３は、中央折曲誘導部４３と一対の側部折曲誘導部４４それぞれとの間に位置し、長手方向Ｘに延びる一対の内側接合部１３、及び一対の側部折曲誘導部４４それぞれより幅方向Ｙの外方に位置し、長手方向Ｘに延びる一対の外側接合部１４，１４において、吸収性コア４０の非肌対向面を被覆する被覆シートと接合されている。【選択図】図３
