An absorbent article has a liquid-permeable front surface sheet, a liquid-impermeable back surface sheet, and an absorber disposed between the front surface sheet and the back surface sheet. The absorbent article includes a groove portion entirely or partly composed of a recessed portion, the recessed portion being formed on the front surface sheet side of the absorbent article by integrally joining the front surface sheet and the absorber together, and a flat portion enclosed by the groove portion. A diameter of a maximum inscribed circle inscribed in the flat portion is at least five times and at most 20 times as large as a width of the groove portion along a radial direction of the maximum inscribed circle.
