An absorbent article for a pet comprising: a longitudinal direction and a lateral direction; a body facing surface and a non-body facing surface opposite to each other; a belly facing region; a back facing region; an intermediate region positioned between the belly facing region and the back facing region in the longitudinal direction; a liquid permeable inner layer sheet; a liquid impermeable outer layer sheet; and an absorbent core provided between the inner layer sheet and the outer layer sheet, wherein the absorbent core is provided only in a portion closer to the belly facing region than a cutting line in which a tail of the pet is inserted, the cutting line being positioned in the intermediate region, and wherein the body facing surface of the inner layer sheet has an area, at least overlapping the absorbent core in plan view, in which a recessed-and-protruded region is positioned, the recessed-and-protruded region including ridges and grooves that are alternately arranged side by side in the lateral direction while extending in the longitudinal direction, and the cutting line partially extends so as to cross a plurality of ridges and a plurality of grooves; characterized in that the inner layer sheet is formed of fiber nonwoven fabrics having fiber orientation along the longitudinal direction in which the recessed-and-protruded region extends; the absorbent core includes first and second ends (51A,51B) separated from each other and opposite to each other in the longitudinal direction and a intermediate portion positioned between the first and the second ends (51A,51B); and the absorbent core is provided in the intermediate portion with a first narrow portion positioned on the side of the first end and a second narrow portion positioned on the side of the second end (51 B). a longitudinal direction and a lateral direction; a body facing surface and a non-body facing surface opposite to each other; a belly facing region; a back facing region; an intermediate region positioned between the belly facing region and the back facing region in the longitudinal direction; a liquid permeable inner layer sheet; a liquid impermeable outer layer sheet; and an absorbent core provided between the inner layer sheet and the outer layer sheet, wherein the absorbent core is provided only in a portion closer to the belly facing region than a cutting line in which a tail of the pet is inserted, the cutting line being positioned in the intermediate region, and wherein the body facing surface of the inner layer sheet has an area, at least overlapping the absorbent core in plan view, in which a recessed-and-protruded region is positioned, the recessed-and-protruded region including ridges and grooves that are alternately arranged side by side in the lateral direction while extending in the longitudinal direction, and the cutting line partially extends so as to cross a plurality of ridges and a plurality of grooves; characterized in that the inner layer sheet is formed of fiber nonwoven fabrics having fiber orientation along the longitudinal direction in which the recessed-and-protruded region extends; the absorbent core includes first and second ends (51A,51B) separated from each other and opposite to each other in the longitudinal direction and a intermediate portion positioned between the first and the second ends (51A,51B); and the absorbent core is provided in the intermediate portion with a first narrow portion positioned on the side of the first end and a second narrow portion positioned on the side of the second end (51 B).