A battery (100, 100') comprising: an electrode body; a lead electrically connected to the electrode body; a container member housing the electrode body and the lead and comprising a terminal-connecting part having a thickness of 0.3 mm or less, the terminal-connecting part comprising a through hole and a rising part extending toward an inside of the container member from an edge part of the through hole, and the rising part comprising a diameter-reduction part having a diameter reduced along a direction toward the inside of the container member from the edge part of the through hole; a gasket comprising a hollow shaft inserted into the rising part; an external terminal comprising a first end part and a second end part and comprising a terminal shaft extending to an axial direction toward the second end part from the first end part, wherein the terminal shaft passes through the shaft of the gasket, and is electrically connected to the lead, and the terminal shaft comprises a diameter-reduction part having a diameter reduced along the axial direction; and a restraining member restraining at least a part of the diameter-reduction part of the terminal shaft via the diameter-reduction part of the rising part and the shaft of the gasket, wherein an inclination angle of the diameter-reduction part of the rising part to the axial direction is larger than an inclination angle of the diameter-reduction part of the terminal shaft to the axial direction, wherein the restraining member transmits a counteraction against a pressure from the diameter-reduction part of the terminal shaft as a restraining force to the gasket through the diameter-reduction part of the rising part, wherein the shaft of the gasket comprises portions having different thicknesses, and wherein a portion sandwiched between the diameter-reduction part of the rising part and the diameter-reduction part of the terminal shaft in the shaft of the gasket comprises a first portion having a maximum thickness and a second portion having a minimum thickness, and the first portion is disposed closer to the edge part of the through hole of the terminal-connecting part than the second portion. an electrode body; a lead electrically connected to the electrode body; a container member housing the electrode body and the lead and comprising a terminal-connecting part having a thickness of 0.3 mm or less, the terminal-connecting part comprising a through hole and a rising part extending toward an inside of the container member from an edge part of the through hole, and the rising part comprising a diameter-reduction part having a diameter reduced along a direction toward the inside of the container member from the edge part of the through hole; a gasket comprising a hollow shaft inserted into the rising part; an external terminal comprising a first end part and a second end part and comprising a terminal shaft extending to an axial direction toward the second end part from the first end part, wherein the terminal shaft passes through the shaft of the gasket, and is electrically connected to the lead, and the terminal shaft comprises a diameter-reduction part having a diameter reduced along the axial direction; and a restraining member restraining at least a part of the diameter-reduction part of the terminal shaft via the diameter-reduction part of the rising part and the shaft of the gasket, wherein an inclination angle of the diameter-reduction part of the rising part to the axial direction is larger than an inclination angle of the diameter-reduction part of the terminal shaft to the axial direction, wherein the restraining member transmits a counteraction against a pressure from the diameter-reduction part of the terminal shaft as a restraining force to the gasket through the diameter-reduction part of the rising part, wherein the shaft of the gasket comprises portions having different thicknesses, and wherein a portion sandwiched between the diameter-reduction part of the rising part and the diameter-reduction part of the terminal shaft in the shaft of the gasket comprises a first portion having a maximum thickness and a second portion having a minimum thickness, and the first portion is disposed closer to the edge part of the through hole of the terminal-connecting part than the second portion.