There is provided a multi-mirror-system for an illumination system, especially for lithography with wavelengths ≦193 nm. The system includes light rays traveling along a light path from an object plane to an image plane, andan arc-shaped field in the image plane, whereby a radial direction in the middle of the arc-shaped field defines a scanning direction. The first mirror and the second mirror are arranged in the light path in such a position and having such a shape, that the edge sharpness of the arc-shaped field in the image plane is smaller than 5 mm in the scanning direction. Furthermore, the light rays are impinging on the first mirror and the second mirror with incidence angles ≦30° or ≧60° relative to a surface normal of the first and second mirror.