Patent ID: 8353415

Claim:
A biaxially stretched, blow molded synthetic resin bottle with a body having a same diameter as a heel wall portion, and with a bottom comprising a sunken bottom portion which is formed by contouring and concaving a bottom plate upward in a direction of bottle inside, starting from an inner peripheral edge of a ground contact portion disposed along peripheral foot, the sunken bottom portion being capable of drawing upward in a reversible manner when internal pressure goes down, wherein this sunken bottom portion is characterized by and comprises: an inner peripheral wall portion standing from near the inner peripheral edge of the ground contact portion disposed along the peripheral foot, a central concave portion disposed at a center of the bottom, a reversible wall portion formed in a ring shape having horizontal flat surfaces, which is reversibly deformable into an upward drawing state and which is connected to a base of the central concave portion, and a circular rib wall portion is disposed between the reversible wall portion and an upper end of the inner peripheral wall portion so as to perform a function as a peripheral rib.