A rechargeable battery includes a battery case, a cover that closes an open end of the battery case, and a power collection terminal arranged on the cover to supply power from a power generating element to an external terminal. The power collection terminal extends through a gasket arranged on a lower surface of the cover, an insulator arranged on an upper surface of the cover, and the external terminal arranged on an upper surface of the insulator. An annular sealing member is held between the lower surface of the cover and the gasket. The insulator is a resin-molded component. The insulator includes a through hole defined by an inner wall that includes a lower open end, an upper open end, and a central portion. At least one of the lower open end and the upper open end has a larger diameter than the central portion.