[Object] To allow the back side part of the absorbent article to be deformed easily along the shape of a body and improve fittedness.[Solution to Problem] On the skin-side surface of the back side part of an absorbent body 4, there are formed a front-surface side concave groove 10 recessed to the non-skin side in a given pattern and a plurality of partitioned absorption parts 11 partitioned by the front-surface side concave groove 10. In addition, at a position facing the gluteal cleft on the non-skin-side surface of the back side part of the absorbent body 4, there is formed gluteal cleft-facing concave groove 12 recessed to the skin side. The front-surface side concave groove 10 includes a plurality of longitudinal direction concave grooves 13 arranged along the substantially longitudinal direction of a sanitary napkin 1 with intervals in the width direction and a plurality of width direction concave grooves 14 arranged along the substantially width direction of the sanitary napkin 1 with intervals in the longitudinal direction. The longitudinal direction concave groove 13 is formed in a radial form inclined outward in the width direction from the front side toward the back side of the sanitary napkin 1.
