The invention relates to application of enamel layers in the form of powder in an electric field and subsequent firing. A cleaned surface of a steel product is covered with a ground coat enamel layer in the form of powder in the electric field by an application gun until the layer reaches a thickness of 100 to 150 μm. Subsequently, the electric field is interrupted in order to reduce a space charge around the metal product and, in the same manner, a minimum of another two layers of cover coat enamel powder is applied until a thickness of the total enamel powder layer reaches a minimum of 750 μm, wherein the electric field is interrupted each time between each steps of cover coat enamel powder application.