PROBLEM TO BE SOLVED: To fit along a bodily shape wherein the front side and the rear side of a body have different shapes, to make fitting easy by following a motion of the body, and to improve a wear feeling, in an absorbent article wherein outer shapes of flap parts in at least a front side portion and a back side portion of the absorbent article are wavelike shape lines each comprising a combination between projecting curve parts and recessed curve parts.SOLUTION: The wavelike shape lines 10 are shape lines having central projecting curve parts 11 in width direction center parts of a sanitary napkin 1 and having recessed curve parts 12 and projecting curve parts 13 on both sides thereof in symmetric arrangement. The central projecting curve part 11 of the front side portion is formed at a curvature radius R and an arc length L relatively larger than the central projecting curve part 11 of the back side portion. That is, they satisfy the following relation: the curvature radius Rf of the central projecting curve part 11 of the front side portion>the curvature radius Rb of the central projecting curve part 11 of the back side portion and the arc length Lf od the central projecting curve part 11 of the front side portion>the arc length Lb of the central projecting curve part 11 of the back side portion.
