Replacement device for an optical element

A system, comprising:

• an apparatus part of a lithographic projection exposure apparatus, the apparatus part comprising:
• a housing;
• a mount;
• a holding structure configured to hold an optical element in the mount, the holding structure being different from the housing;
• and
• a clamping device configured to provide clamping forces to fix the optical element relative to the holding structure, the clamping forces of the clamping device being such that they essentially do not act on the holding structure;
• and
• a receptacle for the optical element, the receptacle being at least indirectly mounted in the lithographic projection exposure apparatus,
• wherein:
• the housing has an opening through which the receptacle can be moved from being inside the housing to being outside the housing;
• in a first position, the receptacle and the optical element are inside the housing;
• in a second position, the receptacle and the optical element are outside the housing;
• the clamping device is inside the housing when the receptacle is in the first position;
• and
• the clamping device is inside the housing when the receptacle is in the second position.