Abstract: The invention relates to a nozzle for the surface treatment of metal workpieces, in particular for the powder build-up welding or thin-layer alloying of highly stressed metal components, which can be selectively connected to a mirror-focused or a lens-focused high-energy beam installation, preferably a high-performance laser installation, by using the cooling medium units, inert gas lines and powder conveyors/extractors provided. In comparison with known laser spray nozzles, the nozzle guarantees a directionally-independent coating of highly stressed metal components with a regular annular distribution of the stream of powder-delivery gas and inert gas supplied.