A bottle formed of a synthetic resin material into a cylindrical shape with a bottom, a bottom wall portion of the bottom comprising: a ground contact portion which is positioned at an outer circumferential edge portion of the bottom wall portion; a rising peripheral wall portion which is connected to the ground contact portion from an inner side of a bottle radial direction and extends upward; a ring-shaped movable wall portion which protrudes from an upper end portion of the rising peripheral wall portion to the inner side of the bottle radial direction; and a depressed peripheral wall portion which extends upward from an inner end portion of the ring-shaped movable wall portion in the bottle radial direction, wherein the ring-shaped movable wall portion is rotatably disposed about a connecting part with the rising peripheral wall portion so as to move the depressed peripheral wall portion upward, wherein a concave and convex portion is formed over an entire circumference of the rising peripheral wall portion, and wherein a concave part of the concave and convex portion is a vertical rib which is depressed to the inner side of the bottle radial direction, the rising peripheral wall portion is provided with a plurality of the vertical ribs, and each of the vertical ribs is formed into a vertically long shape over part from the ground contact portion to the connecting part of the rising peripheral wall portion with the ring-shaped movable wall portion and opened upward, characterized in that the verticals ribs are formed such that a first circumferential length of the rising peripheral wall portion including the verticals ribs is within a range from 1.05 to 1.3 times as long as a second circumferential length of the rising peripheral wall portion excluding the verticals ribs, wherein the movable wall portion revolves about the connecting part with the rising peripheral wall portion to increase or decrease in a flexible manner the diameter of the upper end portion side of the rising peripheral wall portion by the movement of the upper end portion of the rising peripheral wall portion in the bottle radial direction. a ground contact portion which is positioned at an outer circumferential edge portion of the bottom wall portion; a rising peripheral wall portion which is connected to the ground contact portion from an inner side of a bottle radial direction and extends upward; a ring-shaped movable wall portion which protrudes from an upper end portion of the rising peripheral wall portion to the inner side of the bottle radial direction; and a depressed peripheral wall portion which extends upward from an inner end portion of the ring-shaped movable wall portion in the bottle radial direction, wherein the ring-shaped movable wall portion is rotatably disposed about a connecting part with the rising peripheral wall portion so as to move the depressed peripheral wall portion upward, wherein a concave and convex portion is formed over an entire circumference of the rising peripheral wall portion, and wherein a concave part of the concave and convex portion is a vertical rib which is depressed to the inner side of the bottle radial direction, the rising peripheral wall portion is provided with a plurality of the vertical ribs, and each of the vertical ribs is formed into a vertically long shape over part from the ground contact portion to the connecting part of the rising peripheral wall portion with the ring-shaped movable wall portion and opened upward, characterized in that the verticals ribs are formed such that a first circumferential length of the rising peripheral wall portion including the verticals ribs is within a range from 1.05 to 1.3 times as long as a second circumferential length of the rising peripheral wall portion excluding the verticals ribs, wherein the movable wall portion revolves about the connecting part with the rising peripheral wall portion to increase or decrease in a flexible manner the diameter of the upper end portion side of the rising peripheral wall portion by the movement of the upper end portion of the rising peripheral wall portion in the bottle radial direction.