A disposable diaper comprising an absorbent member containing an oblong absorbent core, the diaper having a front portion, a crotch portion, and a rear portion adapted to be worn about the front, the crotch, and the rear, respectively, of a wearer, the absorbent core having a high basis weight region with a high basis weight of an absorbent core-forming material in a laterally middle part of the crotch portion and a low basis weight region having a lower basis weight of the absorbent core-forming material than the high basis weight region in both lateral sides of the high basis weight region, the absorbent core having a central bending-inducing region extending in its longitudinal direction in the form of a slit, a groove, or a fiber-free region in the high basis weight region thereof and a side bending-inducing region in the form of a fiber-free region in each of the low basis weight regions thereof, wherein the fiber-free region is a region where any absorbent core-forming material is not present or wherein the fiber-free region is a region where an absorbent core-forming material is present in a total amount of 50 g/m 2 or less, characterized in that the central bending-inducing region extending in the longitudinal direction of the absorbent core toward the front end of the absorbent core beyond the front end of each side bending-inducing region, the side bending-inducing regions extending in the longitudinal direction of the absorbent core toward the rear end of the absorbent core beyond the rear end of the central bending-inducing region, the absorbent core containing an absorbent polymer, the absorbent member comprising the absorbent core and a core wrap sheet covering the upper and the lower side of the absorbent core, the part of the core wrap sheet overlying the absorbent core and the part of the core wrap sheet underlying the absorbent core being bonded to each other in each side bending-inducing region, and the part of the core wrap sheet overlying the absorbent core is not bonded to a member located right thereunder in the central bending-inducing region. the absorbent core having a high basis weight region with a high basis weight of an absorbent core-forming material in a laterally middle part of the crotch portion and a low basis weight region having a lower basis weight of the absorbent core-forming material than the high basis weight region in both lateral sides of the high basis weight region, the absorbent core having a central bending-inducing region extending in its longitudinal direction in the form of a slit, a groove, or a fiber-free region in the high basis weight region thereof and a side bending-inducing region in the form of a fiber-free region in each of the low basis weight regions thereof, wherein the fiber-free region is a region where any absorbent core-forming material is not present or wherein the fiber-free region is a region where an absorbent core-forming material is present in a total amount of 50 g/m 2 or less, characterized in that the central bending-inducing region extending in the longitudinal direction of the absorbent core toward the front end of the absorbent core beyond the front end of each side bending-inducing region, the side bending-inducing regions extending in the longitudinal direction of the absorbent core toward the rear end of the absorbent core beyond the rear end of the central bending-inducing region, the absorbent core containing an absorbent polymer, the absorbent member comprising the absorbent core and a core wrap sheet covering the upper and the lower side of the absorbent core, the part of the core wrap sheet overlying the absorbent core and the part of the core wrap sheet underlying the absorbent core being bonded to each other in each side bending-inducing region, and the part of the core wrap sheet overlying the absorbent core is not bonded to a member located right thereunder in the central bending-inducing region.