An energy storage device includes an electrode assembly, a case, a terminal part, and a current collector, wherein the terminal part has: an external terminal having at least a part exposed to outside of the case; a conduction member configured to make the external terminal and the current collector conductive; a decoupling mechanism configured to decouple the conduction member, or hinder a conduction state of the conduction member; and an auxiliary terminal disposed spaced from the external terminal, and having at least a part exposed to the outside of the case, the auxiliary terminal being electrically connected to the current collector.