The diaper (1) includes an absorbent main body (10) having a lengthwise direction and being folded in two at a predetermined location in the lengthwise direction as well as having the lengthwise direction arranged along the vertical direction, an abdomen side waist part (31) overlapping and being joined to a non-skin side face of an end part on one side in the lengthwise direction of the absorbent main body (10), and a back side waist part (41) overlapping and being joined to a non-skin side face of an end part on another side in the lengthwise direction of the absorbent main body (10). The absorbent main body (10) includes an absorbent core (11c) that absorbs liquid and a sheet-like flap part (10f) that extends horizontally outward with respect to the absorbent core (11c). The flap part (10f) includes on each of the one side and the other side in the lengthwise direction, respective Z-shape folded portions (10fZ, 10fZ) that are fixed in a state folded along the horizontal direction in a Z-shape. The portions located horizontally outward with respect to the absorbent core (11c) in the abdomen side waist part (31) and the back side waist part (41) respectively have the Z-shape folded portions (10fZ, 10fZ) of the flap part fixed.
