A bottle (11, 21) formed of a synthetic resin material in a cylindrical shape with a bottom (114, 214) having a bottom wall portion (119, 219), the bottom wall portion (119, 219) comprising: a grounding portion (118, 218) located at an outer circumferential edge of the bottom wall portion (119, 219); a rising circumferential wall portion (121, 221) that is connected from a bottle radial inner side to the grounding portion (118, 218) and extends; an annular movable wall portion (122, 222) protruding from an upper end of the rising circumferential wall portion (121, 221) towards the bottle radial inner side and a recessed circumferential wall portion (123, 223) that is connected from the bottle radial inner side to the movable wall portion (122, 222) and extends upward wherein: the movable wall portion (122, 222) is free to rotate around a curved surface part (125, 225) connected to the rising circumferential wall portion (121, 221) so as to move the recessed circumferential wall portion (123, 223) in an upward direction, the curved surface part (125, 225) protrudes upward, and the rising circumferential wall portion (121, 221) extends upwardly and inwardly from the grounding portion (118, 218) to the curved surface part (125, 225), an inclined angle (θ) thereof is equal to or less than 10° with respect to a central longitudinal axis of the bottle (11, 21), characterized in that the contents of the bottle are equal to or less than one liter and in that a grounding diameter is equal to or less than 85 mm,_and a height (T, H2) from the grounding portion (118, 218) to the curved surface part (125, 225) exceeds 7.5 mm. a grounding portion (118, 218) located at an outer circumferential edge of the bottom wall portion (119, 219); a rising circumferential wall portion (121, 221) that is connected from a bottle radial inner side to the grounding portion (118, 218) and extends; an annular movable wall portion (122, 222) protruding from an upper end of the rising circumferential wall portion (121, 221) towards the bottle radial inner side and a recessed circumferential wall portion (123, 223) that is connected from the bottle radial inner side to the movable wall portion (122, 222) and extends upward wherein: the movable wall portion (122, 222) is free to rotate around a curved surface part (125, 225) connected to the rising circumferential wall portion (121, 221) so as to move the recessed circumferential wall portion (123, 223) in an upward direction, the curved surface part (125, 225) protrudes upward, and the rising circumferential wall portion (121, 221) extends upwardly and inwardly from the grounding portion (118, 218) to the curved surface part (125, 225), an inclined angle (θ) thereof is equal to or less than 10° with respect to a central longitudinal axis of the bottle (11, 21), characterized in that the contents of the bottle are equal to or less than one liter and in that a grounding diameter is equal to or less than 85 mm,_and a height (T, H2) from the grounding portion (118, 218) to the curved surface part (125, 225) exceeds 7.5 mm. the movable wall portion (122, 222) is free to rotate around a curved surface part (125, 225) connected to the rising circumferential wall portion (121, 221) so as to move the recessed circumferential wall portion (123, 223) in an upward direction, the curved surface part (125, 225) protrudes upward, and the rising circumferential wall portion (121, 221) extends upwardly and inwardly from the grounding portion (118, 218) to the curved surface part (125, 225), an inclined angle (θ) thereof is equal to or less than 10° with respect to a central longitudinal axis of the bottle (11, 21), characterized in that the contents of the bottle are equal to or less than one liter and in that a grounding diameter is equal to or less than 85 mm,_and a height (T, H2) from the grounding portion (118, 218) to the curved surface part (125, 225) exceeds 7.5 mm.