PURPOSE:To increase the storage performance and electrolyte leakage resistant performance of a battery by using a clad material of aluminium and stainless steel for the positive case of an organic electrolyte battery in which carbon fluoride is used as positive active material and lithium as negative active material. CONSTITUTION:A cald material of aluminium and stainless steel is used for a positive case 3 which is used as a container accommodating a power generating element. This clad material has good drawability and has elastic strength 5.5 times and tensile strength 21 times larger than aluminium. When the opening of a battery is sealed via a gasket 7 made of polypropylene or butadiene rubber, mechanical strength and sealability are increased. Therefore, the storage performance and electrolyte leakage resistant performance of a battery is increased.