A shaped or unshaped article of a non-ferrous metal sheet preferably aluminum having an organic, surface coating film containing conductive and/or semiconductive fine particles, preferably molybdenum dissulfide is integrally bonded with a shaped or unshaped article of a steel sheet having or not having an organic, surface coating film; and this integrated body is subjected simultaneously to electrodeposition coating.The non-ferrous metal sheet having an organic, surface coating film containing conductive and/or semiconductive, fine particles shows excellent electrodeposition coating characteristics which can be easily regulated. Hence, integral coating after bounding with a steel sheet gives the same degree of film thickness and surface smoothness on both of the non-ferrous metal and steel sheets. This method is particularly suitable for the coating of automobile bodies integrally composed of non-ferrous metal and steel sheets ensuring energy- and labor-saving and giving final products of uniform finish.