A method of applying a covering layer and reflective optical element

The invention relates to a method for applying a top view (5) onto a reflective coating (7) or to a substrate of an optical element (1) for reflecting light which has at least one wavelength in the EUV wavelength range, the method comprising: applying the outer layer (5) by means of atomic layer deposition, preferably by means of spatial atomic layer deposition, preferably before applying the cover layer (5) at least one protective layer (4) on the reflecting coating (7) is applied which contains a metal, particularly a noble metal. The invention also relates to an optical element (1) for reflecting light which has at least one wavelength in the EUV wavelength range, comprising: a reflective coating (7) and one on the reflective coating (7) or (to a substrate of the optical element 1) by atomic layer deposition applied covering layer (5), preferably having a thickness of less than 10 monolayers, less than 5 monolayers or exactly one monolayer has.