Abstract: An optical element including a reflective coating is disclosed. In an embodiment the reflective coating includes an adhesion-promoting layer, an at least partially reflective silver layer disposed on the adhesion-promoting layer and a protective layer system disposed on the silver layer, wherein the protective layer system includes a plurality of dielectric layers, wherein the dielectric layers include at least one first layer and at least one second layer, wherein the first layer and the second layer have a different resistance to at least two different contamination substances, wherein the dielectric layers have a thickness of not more than 30 nm, and wherein a number of the dielectric layers amounts to at least five.