The present invention relates to a method for measuring metal ion permeability of a polymer film, comprising the steps of: applying a voltage to the polymer film at a temperature of 5° C. to 250° C., while one side of the polymer film is brought into contact with an electrolyte comprising metal ions, an organic solvent and an aqueous solvent; and measuring the change rate of resistance or change rate of current of the polymer film according to time, after the voltage is applied, and a device for measuring metal ion permeability of a polymer film used therefor.