PURPOSE: To increase current collecting efficiency of negative electrode and prevent flow-out of lithium by arranging lithium serving as a negative electrode inside a metal cup and surrounding the lithium with a metal powder molding and the metal cup.

CONSTITUTION: A negative active material 1 comprising a metallic lithium sheet is arranged inside a metal cup 3. A metal powder molding 2 comprising metal powder alone or its mixture surrounds the lithium sheet 1 with the metal cup 3. Although the lithium is liquefied by operation of battery, its flow-out is prevented by the molding 2 and the cup 3. Since the molding 3 has micropores, lithium is absorbed in the micropores by capillary action and current collecting efficiency of the lithium negative electrode is increased.