An underpants-shaped absorbent article (1) includes an absorbent main body (10), a front waist member (20), and a back waist member (30). The back waist member (30) includes an extending portion (32) that extends downward with respect to joint portions (32) of the front waist member (20) and the back waist member (30) . The extending portion (32) includes an inclining elastic member (37) and a lateral elastic member (38). When viewed in the front-back direction, the inclining elastic member (37) and the lateral elastic member (38) have an overlapping portion where the inclining elastic member (37) and the lateral elastic member (38) overlap each other. Concerning the length (W322) from the left-right-direction side end of the absorbent main body (10) on one side to the left-right-direction side end of the back waist member (30) on the one side, the length (W322) is longer than the left-right-direction length (W10) of the absorbent main body (10) in a state in which the underpants-shaped absorbent article (1) is stretched in the left-right direction.