Abstract: In a method for coating optical elements for systems working with ultraviolet light, the coating process is performed in the evacuable working chamber of a coating system. At least one lock system is provided, equipped with a lock chamber that can be evacuated and, if desired, separated from the working chamber or connected to the working chamber in order to introduce optical elements. After the optical elements are moved into the lock chamber, different treatment steps may be performed there on the elements that were, or will be, coated. The treatment may include in particular cleansing with ultraviolet light, controlled heating or cooling, and/or measurement of at least one optical property of the optical elements. Using the lock chambers for the pre-treatment and post-treatment of optical elements immediately before or after a coating process permits improved control of the coating process and production of elements of highest quality with minimal total processing time.