In view of the challenges specific to an absorbent article with leakage prevention grooves, the disclosed absorbent article seeks to mitigate the reduction in flexibility of the entire absorbent body engendered by the leakage prevention grooves and, while preventing the spread of liquid due to side leakage, to effectively use the absorbent core inside and outside of the leakage prevention grooves depending on the amount of excretion. The absorbent article is a hygienic napkin which has a liquid permeable front surface sheet disposed on the side of the surface contacting the skin, a liquid permeable rear surface sheet disposed on the side of the surface not contacting the skin, and an absorbent core disposed between the aforementioned two sheets. The aforementioned absorbent core has a length direction and a width direction orthogonal thereto. Said absorbent core has multiple separation gaps extending along the width direction thereof, and the aforementioned separation gaps of the aforementioned absorbent core are also formed along the length direction thereof. The aforementioned absorbent core is formed from a collection of horizontally and vertically independent small absorption units. Leakage prevention grooves are formed in said absorbent core extending in the length direction, traversing one or more of the aforementioned separation gaps, and compressed, along with the aforementioned front surface sheet, from the side of said front surface sheet.