A bottle (1, 40) formed of a synthetic resin material in a shape of a bottomed cylinder by blow molding, the bottle comprising: a bottom wall part of a bottom part including: a grounding part located at an outer circumferential edge of the bottom wall part, a standing peripheral wall part configured to connect to the grounding part from a radial inner side of the bottle and to extend upward, an annular movable wall part configured to protrude from an upper end of the standing peripheral wall part toward the radial inner side of the bottle, and a depression peripheral wall part configured to extend upward from an inner end of the movable wall part in a radial direction of the bottle, wherein the movable wall part is disposed to freely pivot around a connection part connected with the standing peripheral wall part so as to move the depression peripheral wall part in an upward direction, and the depression peripheral wall part is formed to have multiple stages, the depression peripheral wall part is formed with an angular cylindrical part of a polygonal shape in which a plurality of overhang parts projecting toward the radial inner side of the bottle are formed in succession in the circumferential direction of the bottle, and thereby a shape of the angular cylindrical part when viewed from a cross section thereof is configured so that midsections located between the overhang parts adjoining each other in the circumferential direction of the bottle become corner parts and so that the overhang parts become side parts, characterized in that when viewed from a longitudinal section of the angular cylindrical part, each of the midsections and the overhang parts is formed in a shape of a curved surface protruding toward the radial inner side of the bottle, and a radius of curvature of the midsection is greater than that of the overhang part. a grounding part located at an outer circumferential edge of the bottom wall part, a standing peripheral wall part configured to connect to the grounding part from a radial inner side of the bottle and to extend upward, an annular movable wall part configured to protrude from an upper end of the standing peripheral wall part toward the radial inner side of the bottle, and a depression peripheral wall part configured to extend upward from an inner end of the movable wall part in a radial direction of the bottle, wherein the movable wall part is disposed to freely pivot around a connection part connected with the standing peripheral wall part so as to move the depression peripheral wall part in an upward direction, and the depression peripheral wall part is formed to have multiple stages, the depression peripheral wall part is formed with an angular cylindrical part of a polygonal shape in which a plurality of overhang parts projecting toward the radial inner side of the bottle are formed in succession in the circumferential direction of the bottle, and thereby a shape of the angular cylindrical part when viewed from a cross section thereof is configured so that midsections located between the overhang parts adjoining each other in the circumferential direction of the bottle become corner parts and so that the overhang parts become side parts, characterized in that when viewed from a longitudinal section of the angular cylindrical part, each of the midsections and the overhang parts is formed in a shape of a curved surface protruding toward the radial inner side of the bottle, and a radius of curvature of the midsection is greater than that of the overhang part.