An absorbent article having a longitudinal direction, a lateral direction, and a thickness direction that are orthogonal to each other, and including a stomach-side portion including a stomach-side sheet member, a back-side portion including a back-side sheet member, and a joining portion (14a, 14b) in which at least one end portion (11a, 11b) of the stomach-side portion and at least one end portion (13a, 13b) of the back-side portion in the lateral direction are joined to each other in a state of being overlapped in the thickness direction along the longitudinal direction, wherein the joining portion (14a, 14b) includes a plurality of fused portions which are separated from each other and disposed along the longitudinal direction, each of the plurality of fused portions includes a core portion in which the stomach-side sheet member and the back-side sheet member are fused to each other in the thickness direction, and a peripheral wall portion in which the stomach-side sheet member and the back-side sheet member are fused to each other in the thickness direction to extend in a tubular shape in the thickness direction from a peripheral edge of the core portion, a surface of the core portion is flat, in a peeling test of the joining portion (14a, 14b) in which one end portion of a sample including the joining portion (14a, 14b) in the longitudinal direction is held by two jigs, and while peeling off the joining portion (14a, 14b) to widen a distance between the two jigs, a load to be applied between the two jigs is measured, a graph showing the load with respect to the distance has a plurality of protruding portions (K k) in which the load temporarily shows local maximum values (F Mk) at respective positions of the plurality of fused portions, and in the peeling test, when the one end portion of the sample in the longitudinal direction is an end portion of either a waist opening side or a leg opening side of the absorbent article, a standard deviation with respect to an average value of the local maximum values (F Mk) in the plurality of the protruding portions (K k) corresponding to the plurality of fused portions is 3 N or less, measured as described in the description. wherein the joining portion (14a, 14b) includes a plurality of fused portions which are separated from each other and disposed along the longitudinal direction, each of the plurality of fused portions includes a core portion in which the stomach-side sheet member and the back-side sheet member are fused to each other in the thickness direction, and a peripheral wall portion in which the stomach-side sheet member and the back-side sheet member are fused to each other in the thickness direction to extend in a tubular shape in the thickness direction from a peripheral edge of the core portion, a surface of the core portion is flat, in a peeling test of the joining portion (14a, 14b) in which one end portion of a sample including the joining portion (14a, 14b) in the longitudinal direction is held by two jigs, and while peeling off the joining portion (14a, 14b) to widen a distance between the two jigs, a load to be applied between the two jigs is measured, a graph showing the load with respect to the distance has a plurality of protruding portions (K k) in which the load temporarily shows local maximum values (F Mk) at respective positions of the plurality of fused portions, and in the peeling test, when the one end portion of the sample in the longitudinal direction is an end portion of either a waist opening side or a leg opening side of the absorbent article, a standard deviation with respect to an average value of the local maximum values (F Mk) in the plurality of the protruding portions (K k) corresponding to the plurality of fused portions is 3 N or less, measured as described in the description.