The invention relates to a device for the microstructured plasma treatment of a film substrate, especially of a plastic film. Said device comprises a rotatably received cylindrical electrode the surface of which contains or consists of metal, especially chromium, the surface having microstructured depressions, a planar high-voltage electrode the surface of which has a shape complementary to that of the cylindrical electrode and can be arranged on a section of the surface of the cylindrical electrode in a substantially form-fit manner, a transport device for transporting the film substrate to be treated between the surface of the cylindrical electrode and the high-voltage electrode, and a device for feeding a process gas to the surface of the cylindrical electrode and to the interspace between the cylindrical electrode and the high-voltage electrode.