The present invention relates to an optical module, in particular facet mirror, comprising an optical element and a supporting structure for supporting the optical element, wherein the supporting structure comprises a positioning device for actively setting a position and/or orientation of the optical element in at least one degree of freedom. The supporting structure comprises a selectively activatable contacting device having at least one contacting unit having a first contact section, wherein the first contact section, in an activated state of the contacting device, contacts a second contact section of the optical element in order to exert a contact force on the optical element, while the first contact section, in a deactivated state of the contacting device is removed from the second contact section.