Provided is a battery packaging material which is slim, has excellent moldability, effectively prevents curl after molding, and moreover, is capable of imparting sufficient surface insulation to a battery. This battery packaging material is configured from a laminate which is at least provided with a polyester film layer, an aluminum alloy foil layer, and a thermally-fusible resin layer in this order. The thickness of the polyester film layer is 23-27 µm, the thickness of the aluminum alloy foil layer is 33-37 µm, the thickness of the thermally-fusible resin layer is 55-65 µm, the thickness of the laminate is 130 µm or less, and the insulation breakdown voltage of the polyester film layer-side surface is 13 kV or greater.