A disposable diaper having a longitudinal direction and a transverse direction and a longitudinal axis (P-P) extending in the longitudinal direction to bisect a dimension in the transverse direction, and comprising a chassis including a skin-facing surface and a non-skin-facing surface, a front waist region, a rear waist region, a crotch region lying between the front and rear waist regions (11,12) and a liquid-absorbent structure extending in the longitudinal direction at least in the crotch region, characterized in that: the chassis further includes a first sheet, a second sheet and a pair of first leg elastics and a pair of second leg elastics both pairs being interposed between the first sheet and the second sheet so as to be symmetric about the longitudinal axis (P-P), a main portion and a pair of lateral elastic regions folded so as to face the main portion and attached to only front and rear ends in the longitudinal direction of the main portion wherein the first leg elastics and the second leg elastics are arranged in the lateral elastic regions; the first leg elastics are arranged so as to be relatively close to the longitudinal axis (P-P) as viewed in the transverse direction; the second leg elastics are arranged at a distance from the longitudinal axis (P-P) as viewed in the transverse direction larger than a distance from the longitudinal axis (P-P) at which the first leg elastics are arranged and have rectilinear portions extending in the longitudinal direction at least in a portion of the crotch region close to the front waist region and curved portions spaced outwardly from each other in the rear waist region side ends of the rectilinear portions; a portion of the crotch region close to the rear waist region has first non-contractile regions respectively lying between the first leg elastics and the second leg elastics; the rear waist region includes a pair of elastic belt panels (16,17) extending outwardly from the lateral edges of the chassis in the transverse direction and a waist pocket panel through which the inner lateral edges of the respective lateral elastic regions are connected to each other wherein the waist pocket panel is prepared contiguously to or separately of the elastic belt panels (16, 17); each of the elastic belt panels(16,17) is provided with a plurality of first waist elastics spaced apart from each other in the longitudinal direction and extending in the transverse direction; the waist pocket panel (16,17) is provided with a plurality of second waist elastics spaced apart from each other in the longitudinal direction and extending in the transverse direction; the rear waist region has second non-contractile regions lying the respective elastic belt panels (16, 17) and the waist pocket panel; and the first non-contractile regions and the second non-contractile regions are contiguous to each other in the longitudinal direction. the chassis further includes a first sheet, a second sheet and a pair of first leg elastics and a pair of second leg elastics both pairs being interposed between the first sheet and the second sheet so as to be symmetric about the longitudinal axis (P-P), a main portion and a pair of lateral elastic regions folded so as to face the main portion and attached to only front and rear ends in the longitudinal direction of the main portion wherein the first leg elastics and the second leg elastics are arranged in the lateral elastic regions; the first leg elastics are arranged so as to be relatively close to the longitudinal axis (P-P) as viewed in the transverse direction; the second leg elastics are arranged at a distance from the longitudinal axis (P-P) as viewed in the transverse direction larger than a distance from the longitudinal axis (P-P) at which the first leg elastics are arranged and have rectilinear portions extending in the longitudinal direction at least in a portion of the crotch region close to the front waist region and curved portions spaced outwardly from each other in the rear waist region side ends of the rectilinear portions; a portion of the crotch region close to the rear waist region has first non-contractile regions respectively lying between the first leg elastics and the second leg elastics; the rear waist region includes a pair of elastic belt panels (16,17) extending outwardly from the lateral edges of the chassis in the transverse direction and a waist pocket panel through which the inner lateral edges of the respective lateral elastic regions are connected to each other wherein the waist pocket panel is prepared contiguously to or separately of the elastic belt panels (16, 17); each of the elastic belt panels(16,17) is provided with a plurality of first waist elastics spaced apart from each other in the longitudinal direction and extending in the transverse direction; the waist pocket panel (16,17) is provided with a plurality of second waist elastics spaced apart from each other in the longitudinal direction and extending in the transverse direction; the rear waist region has second non-contractile regions lying the respective elastic belt panels (16, 17) and the waist pocket panel; and the first non-contractile regions and the second non-contractile regions are contiguous to each other in the longitudinal direction.