The invention relates to a battery and a battery manufacturing method. The battery manufacturing method includes assembling an internal terminal, a gasket, a battery case component, an insulator, andan external terminal into a state where a cylindrical part of the gasket is fitted in a mounting hole of the battery case component, a projecting part of the internal terminal is fitted in the cylindrical part of the gasket, the insulator is disposed on an outer surface of the battery case component with the projecting part fitted in a through-hole, and the external terminal is disposed on top ofthe insulator so as to lie on the projecting part. The external terminal is pressed against the projecting part of the internal terminal, and the external terminal or the internal terminal is vibratedto thereby weld together the projecting part and the external terminal in a solid state.