A biaxially stretched, blow molded synthetic resin bottle with a bottom includes a sunken bottom portion that is capable of drawing upward in a reversible manner, when internal pressure goes down. This sunken bottom portion includes an inner peripheral wall portion standing from near an inner edge of a ground contact portion disposed along a peripheral foot, a central concave portion disposed at a center of the bottom, a reversible wall portion in a flat ring shape, which is reversibly deformable into an upward drawing state and which connects an upper end of the inner peripheral wall to the base of the central concave portion, and a circular rib wall portion disposed at a connection between the reversible wall portion and the upper end of the inner peripheral wall portion so as to perform the function as a peripheral rib.