Abstract: Known radiator units for generating ultraviolet radiation, particularly for use in food processing or for the treatment of water, have a UV radiator having a radiator tube made of quartz glass or a UV radiator surrounded by a cylindrical jacket tube made of quartz glass having a radiator tube made of quartz glass. Starting from this background, in order to provide a radiator unit for generating ultraviolet radiation, which is suitable for emitting a high radiation power and is also simple and economical to produce, a contaminant- and water-repellent coating is applied to the radiator tube and/or the jacket tube. This coating is generated by use of silicon dioxide or titanium dioxide nano-particles.