A disposable diaper comprising: a chassis having a longitudinal direction, a transverse direction, a side facing the wearer's skin and a side facing away from the wearer's skin and configurationally comprising a front waist region, a rear waist region, a crotch region extending between said front and rear waist regions (13, 14), a waist-opening and a pair of leg-openings; a liquid-absorbent structure provided on said side facing the wearer's skin of said chassis and extending across said crotch region further into said front and rear waist regions (13, 14), said liquid-absorbent structure containing therein a liquid-absorbent core, wherein each of said front and rear waist regions (13, 14) is sectionalized into an upper elasticized region, an intermediate elasticized region, lower elasticized regions (20A, 20B) and a non-elasticized region extending between the lower elasticized regions (20A, 20B) and in a position opposed to a central zone of said liquid-absorbent core, the intermediate elasticized region extending between the upper elasticized region and the lower elasticized regions (20A, 20B) and outside longitudinally opposite ends-(12a, 12b) of the liquid-absorbent structure, the upper elasticized region is provided with a plurality of first waist elastic members extending along a waist periphery in the transverse direction; the lower elasticized regions (20A, 20B) are respectively provided with a plurality of third waist elastic members extending in the transverse direction across opposite lateral regions of each waist region (13, 14); and the intermediate elasticized region is provided with a plurality of waist elastic members extending in the transverse direction between the first waist elastic members and the third waist elastic members; wherein a relationship of said tensile stress among the upper elastic-cized region, said intermediate elasticized region and said lower elasticized region (20A, 20B) can be represented by said upper elasticized region > the lower elasticized region (20A, 20B) > said intermediate elasticized region; characterized in that in the front waist region, the third waist elastic members extend from opposite side edges in the transverse direction slightly beyond the opposite side edges of the liquid-absorbent structure to opposite side edges of the liquid-absorbent core assembly and not into the central zone; in the rear waist region, the third waist elastic members extend from the opposite side edges and terminate short of the opposite side edges of the liquid-absorbent structure; the waist elastic members (31, 32, 33) are permanently bonded in the transverse direction, at least to the inner surface of an inner layer sheet, under respective tensions given by predetermined extending ratios; and the first waist elastic members are under a tension given by the extending ratio in a range of 200 to 350%, the second waist elastic members are under a tension given by the extending ratio in a range of 160 to 250% and the third waist elastic members are under a tension given by the extending ratio in a range of 250 to 400%. a chassis having a longitudinal direction, a transverse direction, a side facing the wearer's skin and a side facing away from the wearer's skin and configurationally comprising a front waist region, a rear waist region, a crotch region extending between said front and rear waist regions (13, 14), a waist-opening and a pair of leg-openings; a liquid-absorbent structure provided on said side facing the wearer's skin of said chassis and extending across said crotch region further into said front and rear waist regions (13, 14), said liquid-absorbent structure containing therein a liquid-absorbent core, wherein each of said front and rear waist regions (13, 14) is sectionalized into an upper elasticized region, an intermediate elasticized region, lower elasticized regions (20A, 20B) and a non-elasticized region extending between the lower elasticized regions (20A, 20B) and in a position opposed to a central zone of said liquid-absorbent core, the intermediate elasticized region extending between the upper elasticized region and the lower elasticized regions (20A, 20B) and outside longitudinally opposite ends-(12a, 12b) of the liquid-absorbent structure, the intermediate elasticized region extending between the upper elasticized region and the lower elasticized regions (20A, 20B) and outside longitudinally opposite ends-(12a, 12b) of the liquid-absorbent structure, the upper elasticized region is provided with a plurality of first waist elastic members extending along a waist periphery in the transverse direction; the lower elasticized regions (20A, 20B) are respectively provided with a plurality of third waist elastic members extending in the transverse direction across opposite lateral regions of each waist region (13, 14); and the intermediate elasticized region is provided with a plurality of waist elastic members extending in the transverse direction between the first waist elastic members and the third waist elastic members; wherein a relationship of said tensile stress among the upper elastic-cized region, said intermediate elasticized region and said lower elasticized region (20A, 20B) can be represented by said upper elasticized region > the lower elasticized region (20A, 20B) > said intermediate elasticized region;