A disposable diaper (10) is provided with an absorbent body (absorbent body 40) having a pair of first fold lines (FL1) and a pair of second fold lines (FL2), and a back sheet 60a. In a folded state in which the absorbent body has been folded, the absorbent body includes: a first region (401) including the center, in the width direction, of the absorbent body； a pair of second regions (402) which are located between the second fold lines and the first fold lines and are each disposed on a surface side of the first region that faces the skin； and a pair of third regions (403) which are located to the outside, in the width direction, of the second fold lines, and which are each disposed on a surface side of the second region that faces the skin. Outside edges of the third regions are disposed to the outside, in the width direction, of the first fold lines. In the folded state there are provided: first joined portions (R1) where the first region and the second regions are joined； third joined portions (R3) where the third regions and a non-skin surface sheet are joined； and third non-joined portions (NR3) where the third regions and the non-skin surface sheet are not joined, positioned to the inside, in the width direction, of the third joined portions, and to the outside, in the width direction, of the first fold lines. The third non-joined portions extend in the front-back direction of the disposable diaper in a crotch area, and cross the center (1LC) in the front-back direction of the disposable diaper.La présente invention décrit une couche jetable (10) prévue avec un corps absorbant (corps absorbant 40) présentant une paire de premières lignes de pliure (FL1) et une paire de secondes lignes de pliure (FL2), et une feuille dorsale (60a). Sous l'état plié dans lequel le corps absorbant a été plié, le corps absorbant comprend : une première région (401) comprenant le centre, dans le sens de la largeur, du corps absorbant ； une paire de secondes régions (402) qui sont
