A solid body laser has a crystal disk forming its laser active medium. A flat side of the crystal disk is totally reflecting. A resonator mirror configuration includes a partially transparent end mirror and one or more folding mirrors, which are disposed with spatial separation from the crystal disk, and the optical axes of the mirrors extend in an inclined manner on the central axis of the crystal disk in such manner that the laser beam which is diffused inside the resonator mirror configuration impinges upon the folding mirror at an oblique angle.
