A disposable diaper, comprising: a front waistline region; a rear waistline region; a crotch region positioned between the front waistline region and the rear waistline region; an absorber running across the crotch region and extending to the front waistline region and the rear waistline region; a product longitudinal direction from the front waistline region towards the rear waistline region; a product widthwise direction perpendicular to the product longitudinal direction; and a pair of leg hole openings; wherein the disposable diaper further comprises: a pair of leg stretch units formed on the periphery of the leg hole openings that can expand and contract in at least the product longitudinal direction; and a crotch stretch unit formed in an absorber arrangement region provided with the absorber within the crotch region, that can expand and contract in at least the product longitudinal direction; the absorber includes: a first region at least partially arranged in the crotch stretch unit; and a second region arranged adjacent to the first region, at an outer side from the first region in the product longitudinal direction, and having a lower bending rigidity than that of the first region; and a boundary between the first region and the second region is arranged at an outer side from an outer end of the crotch stretch unit, in the product longitudinal direction, and is arranged at an inner side from an outer end of the leg stretch unit, in the product longitudinal direction. a front waistline region; a rear waistline region; a crotch region positioned between the front waistline region and the rear waistline region; an absorber running across the crotch region and extending to the front waistline region and the rear waistline region; a product longitudinal direction from the front waistline region towards the rear waistline region; a product widthwise direction perpendicular to the product longitudinal direction; and a pair of leg hole openings; wherein the disposable diaper further comprises: a pair of leg stretch units formed on the periphery of the leg hole openings that can expand and contract in at least the product longitudinal direction; and a crotch stretch unit formed in an absorber arrangement region provided with the absorber within the crotch region, that can expand and contract in at least the product longitudinal direction; a pair of leg stretch units formed on the periphery of the leg hole openings that can expand and contract in at least the product longitudinal direction; and a crotch stretch unit formed in an absorber arrangement region provided with the absorber within the crotch region, that can expand and contract in at least the product longitudinal direction; the absorber includes: a first region at least partially arranged in the crotch stretch unit; and a second region arranged adjacent to the first region, at an outer side from the first region in the product longitudinal direction, and having a lower bending rigidity than that of the first region; and a first region at least partially arranged in the crotch stretch unit; and a second region arranged adjacent to the first region, at an outer side from the first region in the product longitudinal direction, and having a lower bending rigidity than that of the first region; and a boundary between the first region and the second region is arranged at an outer side from an outer end of the crotch stretch unit, in the product longitudinal direction, and is arranged at an inner side from an outer end of the leg stretch unit, in the product longitudinal direction.