Abstract: To achieve a high adhesive strength of a metallization on an enamel, the surface of the enamel is first roughened and simultaneously treated by ultrasound to remove loose particles. Then the layer is conditioned by a wetting agent, activated and the metal layer is deposited chemically. Particularly good results are obtained when the conditioning and activation of the surface are performed at a temperature slightly elevated above room temperature, about 40.degree. C., for about 5 minutes and the roughening is performed chemically by treating with a 2% solution of ammonium hydrogen fluoride.