An energy storage device including an electrode terminal, and a case having a case first surface on which the electrode terminal is disposed, and a case second surface, a conductive member, and a first insulating member including a facing portion that faces the case second surface in the first direction, and is disposed between the case second surface and the conductive member, and an extending portion extending from the facing portion in a second direction intersecting the first direction are provided, and in a third direction intersecting the first direction and the second direction, the extending portion is disposed closer to the case first surface on which the electrode terminal is disposed than a case third surface facing the case first surface of the case.