Invention provides extending the functional possibilities of a light source with laser pumping due to increasing its spatial and energy stability brightness and the reliability under long-term operation whilst ensuring compactness of the device. The result is achieved due to the fact that a focused laser beam is directed into a region of radiating plasma from the bottom upwards: from the lower wall of a chamber to an upper wall of the chamber which is opposite said lower wall, and the region of radiating plasma is arranged close to the upper wall of the chamber. In embodiments of the invention, the focused laser beam is directed along a vertical axis of symmetry of the walls of the chamber, the region of radiating plasma is produced at an optimally small distance away from the upper wall of the chamber and determined radiation power is maintained via an automated control system.