A self-standing bag (1) is provided, including: a body portion (10) formed of a body member (10A) in a tubular shape; and a bottom portion (12) formed of a half-folded bottom member (12A), in which each of side ends of the bottom member (12A) is bonded to an inner surface of a rear surface portion (20) of the body portion (10), a lower end of the bottom member (12A) is bonded to a lower end of the body portion (10) on an entire circumference of the body portion (10), on the body portion (10) side of the bottom member (12A), an adhesive film (22) for bonding a side end of the bottom member (12A) to the body portion (10) is laminated to cover the entire bottom member (12A), both side ends of the adhesive film (22) respectively protrude from both the side ends of the bottom member (12A) in a width direction, and bonding of the side end of the bottom member (12A) to the inner surface of the body portion (10) is achieved by the adhesive film (22).