An absorbent article comprising: an absorbent body provided between a liquid permeable topsheet and a backsheet ; and at least one concave groove for flowing urine therein formed at a skin side surface along a longitudinal direction, wherein a transverse plane shape of the concave groove satisfies following conditional expressions to : a relationship between a depth h of a bottom surface portion of the concave groove, and a distance S from a bottom end G of the concave groove to an upper end K from which a concavity of the concave groove starts is 1.5h < S; a relationship between a width b of a bottom surface of the concave groove, and a width B of a liquid collection area expressed by a distance between the upper ends K and K at both sides of the concave groove is B ≥ 3b, wherein B = 2S + b; and a relationship between a dimension a of a square concave groove expressed by a product of the width b of the bottom surface of the concave groove and the depth h of the bottom surface portion, and a cross-sectional dimension A of the concave groove is A ≥ 2a, and wherein in the concave groove, a density ρ1 of the absorbent body at the bottom is greater than or equal to 1.5 times of a density ρ2 of the absorbent body at a peripheral general portion which is not compressed. an absorbent body provided between a liquid permeable topsheet and a backsheet ; and at least one concave groove for flowing urine therein formed at a skin side surface along a longitudinal direction, wherein a transverse plane shape of the concave groove satisfies following conditional expressions to : a relationship between a depth h of a bottom surface portion of the concave groove, and a distance S from a bottom end G of the concave groove to an upper end K from which a concavity of the concave groove starts is 1.5h < S; a relationship between a width b of a bottom surface of the concave groove, and a width B of a liquid collection area expressed by a distance between the upper ends K and K at both sides of the concave groove is B ≥ 3b, wherein B = 2S + b; and a relationship between a dimension a of a square concave groove expressed by a product of the width b of the bottom surface of the concave groove and the depth h of the bottom surface portion, and a cross-sectional dimension A of the concave groove is A ≥ 2a, and a relationship between a depth h of a bottom surface portion of the concave groove, and a distance S from a bottom end G of the concave groove to an upper end K from which a concavity of the concave groove starts is 1.5h < S; a relationship between a width b of a bottom surface of the concave groove, and a width B of a liquid collection area expressed by a distance between the upper ends K and K at both sides of the concave groove is B ≥ 3b, wherein B = 2S + b; and a relationship between a dimension a of a square concave groove expressed by a product of the width b of the bottom surface of the concave groove and the depth h of the bottom surface portion, and a cross-sectional dimension A of the concave groove is A ≥ 2a, and wherein in the concave groove, a density ρ1 of the absorbent body at the bottom is greater than or equal to 1.5 times of a density ρ2 of the absorbent body at a peripheral general portion which is not compressed. <EOS>