A substrate made from silicon has a first region and a second region. Through pores are formed in the first region. Pores that do not traverse the substrate are provided in the second region. The production of the work piece is performed with the aid of electrochemical etching of the pores. The entire surface of the substrate is covered with a mask layer that is structured photolithographically on the rear of the substrate. The bottoms of the pores in the second region are etched clear, preferably using KOH.