Abstract: A method for thin film or semiconductor technology, is discussed in which a metallization layer can be provided on an insulating layer, allowing opening of through holes in the insulating layer simultaneously with the same mask. A substrate 1 has a first 3 and a second 4 insulating layer on its surface 2, a cover layer 5 on the second insulating layer 4, a structured mask layer 6 on the cover layer 5, and through openings 7 filled with metal and extending from the rear side of the substrate as far as the substrate surface 2. The mask layer 6 features openings in the areas facing the through openings 7 and in the areas to be covered with a metal layer 8. The cover layer 5 is opened in the areas which are not covered by the structured mask layer 6 by means of a first etching process. Following this, the second insulating layer 4 is laser ablated in the areas facing the filled through openings 7, using dielectric mask.