A battery case material includes a biaxially stretched polyamide film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and an aluminum foil layer interposed between the two film layers. As the biaxially stretched polyamide film, a biaxially stretched polyamide film having a density of 1,132 to 1,158 kg/m3 is used. In the battery case material, excellent formability can be secured without coating a lubrication giving component, and sufficient volume capacity ratio can be obtained.