A vacuum system, in particular an EUV lithography system, includes: a vacuum housing, in which a vacuum environment is formed, and also at least one component (14), e.g., an optical element, having a surface (14a) which is subjected to contaminating particles in the vacuum environment. A surface structure (18) is formed at the surface in order to reduce adhesion of the contaminating particles, said surface structure having pore-shaped depressions (24) separated from one another by webs (25). The optical element has a substrate (19), and a multilayer coating (20) applied to the substrate and configured to reflect EUV radiation (6). The surface structure formed at the surface (14a) of the multilayer coating (20) reduces adhesion of contaminating particles (17) via pore-shaped depressions (24) separated from one another by webs (25).