An absorbent article having a lengthwise direction, a widthwise direction, and a thickness direction that are orthogonal to each other, and comprising: a stomach portion; a back portion; and an absorbent body that is positioned between the stomach portion and the back portion and includes an absorber, wherein the absorber contains superabsorbent polymers and includes a compressed portion that extends in the lengthwise direction, the absorbent body includes a pair of side sheets that are positioned on both sides in the widthwise direction and extend in the lengthwise direction on a surface on a skin side, the pair of side sheets each has fixed regions that are positioned at end portions of each of the side sheets on a front side and a back side in the lengthwise direction and fixed to a surface of the absorbent body, and a leak-proof wall that includes an elastic member extending along the lengthwise direction, positioned between the fixed regions on the front side and the back side of each of the side sheets in the lengthwise direction, and has an end edge on an outer side in the widthwise direction which is fixed to the surface of the absorbent body and an end edge on an inner side in the widthwise direction which is not fixed, and in the lengthwise direction, an end edge on the front side of the compressed portion is positioned on the front side with respect to an end edge on the front side of the leak-proof wall, and an end edge on the back side of the compressed portion is positioned on the back side with respect to an end edge on the back side of the leak-proof wall, wherein the compressed portion has an inclined grid shape formed of a plurality of rhombic shapes that are elongated in the lengthwise direction, the direction of the compressed portion being inclined with respect to the lengthwise direction; wherein at each of both sides in the widthwise direction, a part of the compressed portion is positioned in a region between the fixed regions on the front side and the back side in the lengthwise direction. the absorber contains superabsorbent polymers and includes a compressed portion that extends in the lengthwise direction, the absorbent body includes a pair of side sheets that are positioned on both sides in the widthwise direction and extend in the lengthwise direction on a surface on a skin side, the pair of side sheets each has fixed regions that are positioned at end portions of each of the side sheets on a front side and a back side in the lengthwise direction and fixed to a surface of the absorbent body, and a leak-proof wall that includes an elastic member extending along the lengthwise direction, positioned between the fixed regions on the front side and the back side of each of the side sheets in the lengthwise direction, and has an end edge on an outer side in the widthwise direction which is fixed to the surface of the absorbent body and an end edge on an inner side in the widthwise direction which is not fixed, and in the lengthwise direction, an end edge on the front side of the compressed portion is positioned on the front side with respect to an end edge on the front side of the leak-proof wall, and an end edge on the back side of the compressed portion is positioned on the back side with respect to an end edge on the back side of the leak-proof wall, wherein the compressed portion has an inclined grid shape formed of a plurality of rhombic shapes that are elongated in the lengthwise direction, the direction of the compressed portion being inclined with respect to the lengthwise direction; wherein at each of both sides in the widthwise direction, a part of the compressed portion is positioned in a region between the fixed regions on the front side and the back side in the lengthwise direction.