A packaging material for batteries, which is not susceptible to the formation of a pinhole or cracking during the forming, while having excellent formability, and is effectively suppressed in curling after the forming, which is formed of a laminate with at least a base layer, an adhesive layer, a metal layer and a thermally fusible resin layer in this order, and wherein: the tensile modulus of elasticity of the base layer in one direction and the tensile modulus of elasticity of the base layer in a perpendicular direction in the same plane are both within the range of from 400 N/15 mm to 1,000 N/15 mm (inclusive); and the absolute value of the difference between the tensile modulus of elasticity of the base layer in the one direction and the tensile modulus of elasticity of the base layer in the other is 150 N/15 mm or less.