To provide a battery of such a structure that the inside of the battery vessel can be sealed certainly whereby an excellent safety is assured without extra enlargement of the battery dimensions by installing a positive electrode terminal having a sufficient size.

Through a sealing material having electric insulating property, a positive electrode terminal is installed on a lid plate 1 welded to the battery vessel for sealing the inside of the battery, and a terminal plate 6 connected with the positive electrode terminal is installed on the lid plate over a safety valve, and thereby a sufficient size is secured to the positive electrode terminal and the battery vessel is sealed certainly. In a small space provided relative to an insulating plate on the lid plate, a protection circuit 14 is stored, and thereby a compact battery with excellent safety can be established even in case a failed voltage or failed current is impressed/fed or the battery temperature has risen high.