A battery includes: a battery outer case; an electrode body; and a terminal. The case main body includes a bottomed case main body which has a flat accommodation space and of which one surface is opened, and a sealing plate attached to that one surface of the case main body which is opened. The electrode body is a flat electrode body, is accommodated in the flat accommodation space of the case main body, and has a part to which the terminal is joined. The terminal includes a base end attached to the sealing plate, an intermediate part extending from the base end toward the part to which the terminal is joined, along a surface on one side of the battery outer case, and a tip end joined to the part to which the terminal is joined. The tip end of the terminal is joined to a surface on one side of the part to which the terminal is joined, and pushes the part to which the terminal is joined.