A method is provided for applying a cover layer (9) to a net structure (4) to be used for medical purposes, in particular a thrombosis filter. The net structure (4) is applied to a planar substrate (1) that covers openings (5) of the net structure on one side, wherein the openings (5) across the uncovered side are filled with a sacrificial material (7), in particular copper. The net structure (4) is lifted from the substrate (1). A cover layer (9) is deposited on the surface previously covered by the substrate, and the sacrificial material (7) is removed.
