A method for coating a substrate on one or more sides having catalytically active material producible by material deposition under vacuum in a vacuum chamber, using the following steps: loading a substrate in the chamber evacuating the chamber, cleaning the substrate by introducing a gaseous reducing agent, removing the gaseous reducing agent, applying an intermediate layer by means of vacuum arc evaporation, wherein a substrate comprising the same or similar material is introduced into the vacuum chamber, controlling the chamber temperature, coating by vacuum arc evaporation, a metal taken from the group ruthenium, iridium, titanium and mixtures thereof while oxygen is supplied, in a last step the coated substrate is removed from the chamber, wherein at least 99% of the substrate coating is free of constituents originally contained in the substrate itself, and at least 99% of the coating applied on the intermediate layer is kept free of non-oxidized metals.