A lithography apparatus is disclosed, having at least one mirror arrangement which includes a mirror substrate including a front side with a reflecting surface, a side wall, which extends along a circumference of the mirror substrate from a rear side of the mirror substrate, and mounting elements to mount the mirror arrangement on a structural element of the lithography apparatus. The rear side of the mirror substrate and an inner side of the side wall delimit a cavity. Each of the mounting elements is connected to the mirror arrangement at a connection surface. The relation S/D>0.5 is satisfied at least one of the connection surfaces, wherein D denotes a thickness of the side wall at the connection surface and S denotes the length of the shortest path through the mirror material from the centroid of the connection surface to the rear side of the mirror substrate.