The purpose of the first invention is to provide a packaging material for batteries, which has excellent resistance to electrolyte solution. A packaging material for batteries, which is composed of a laminate that sequentially comprises at least a base layer, an adhesive layer, a metal foil layer and a sealant layer in this order. This packaging material for batteries is able to have excellent resistance to electrolyte solution by disposing an acid-reactive resin layer containing an acid curable resin between the adhesive layer and the metal foil layer and/or between the metal foil layer and the sealant layer.