The present invention provides a disposable diaper improved so as to prevent body waste from leaking sideways without sacrificing a bodily fluid absorbing capacity of a liquid-absorbent structure and to assure appropriate fitness to the wearers body. In each of front and rear waist regions 13, 14, a disposable diaper 10 comprises an upper elasticized region 18 extending in a vicinity of a waist-opening periphery 16a, lower elasticized regions 20A, 20B, intermediate elasticized region 19 extending between the upper elasticized region 18 and the lower elasticized regions 20A, 20B and outside longitudinally opposite ends 12a, 12b of a liquid-absorbent structure 12, and, at least in the front waist region 13 of the front and rear waist regions 13, 14, a non-elasticized region 30 opposed to a central zone of a liquid-absorbent core wherein a tensile stress of the intermediate elasticized region 19 is lower than a tensile stress of the upper elasticized region 18.
