A battery includes: an external terminal protruding outward from a main body; a metal terminal for taking out electric power from inside the main body to the external terminal; and an insulating member for insulation between the main body, and the external terminal and the metal terminal. The metal terminal includes a base portion connected to the inside of the main body and extending along the same plane as one face of the main body from which the external terminal protrudes and an end portion which further extends from the base portion and to which the external terminal is fixed. The external terminal includes a tip end face formed as a sloping face which is low on the end portion side of the metal terminal and high on the base portion side of the metal terminal.