PULL-ON DISPOSABLE DIAPER

A pull-on disposable diaper (1001) includes: an absorbent main body (1010); a front waist portion (1003); a back waist portion (1004); an exterior body (1020) provided on a non- skin side of the absorbent main body (1010); and a leak-proof wall (1050) provided on respective lateral sides of the absorbent main body (1010). The leak-proof walls (1050) each includes a joining part (1061) and a non-joining part (1062); The joining part (1061) is a part in which portions of a surface of each of the leak-proof walls are joined to each other on one side in a thickness direction, and the non- joining part (1062) is a part in which portions of the surface are not joined to each other in the thickness direction. When the exterior body (1020) and the leak-proof walls (1050) are stretched outward in the lateral direction such that the lateral lengths of the exterior body (1020) and the leak- proof walls (1050) are maximum lengths, the lateral protrusion amount (W21) of outward protrusion of the exterior body (1020) from an outermost end (1010e) of the absorbent main body (1010) is smaller than a protrusion amount (W50)of outward protrusion of each of the leak-proof walls (1050) from the outermost end (1010e), at a smallest length position (P20). (Figs. 8A, 8B, 8C)