The high-power radiator includes a discharge space (12) bounded by a metal electrode (8), cooled on one side, and a dielectric (9) and filled with a noble gas or gas mixture, both the dielectric (9) and also the other electrode situated on the surface of the dielectric facing away from the discharge space (12) being transparent for the radiation generated by quiet electric discharges. In this manner, a large-area UV radiator with high efficiency is created which can be operated at high electrical power densities of up to 50 kW/m.sup.2 of active electrode surface.