A disposable diaper 1 has a central slit 45 formed along the lengthwise direction L so that the absorber 40 can be curved to be convex in the inward direction, and a pair of side slits 46L, 46R formed along the lengthwise direction L so that the absorber 40 can be curved to be convex in the outward direction. An average total weight of a water absorbent polymer at the central portion CT and the side edge portion S