This absorbent article improves absorption speed and liquid return suppression in a case where a bodily fluid is repeated absorbed. The absorbent article (1) is provided with an absorbent core (9) that includes highly absorbent polymer particles. The absorbent core comprises a first layer (6) on a non-skin-facing side and a second layer (8) on a skin-facing side. The first layer is provided with: a plurality of groove sections (18) that include a plurality of main groove sections (19) that extend in a longitudinal direction and penetrate in a thickness direction; and a plurality of base sections (20) that extend in the longitudinal direction. The main groove sections and the base sections extend in alternation in a transverse direction. The base sections each comprise a base section inner section (36) that is adjacent to the non-skin-facing side of the second layer and a base section outer section (34) that is adjacent to the non-skin-facing side of the base section inner section. The mean density of the highly absorbent polymer particles contained in the base section outer section is lower than the mean density of the highly absorbent polymer particles contained in the base section inner section.