Abstract: A method for producing a glassy, transparent coating on a substrate by coating the substrate with a solution containing a) a polysilazane of the formula —(SiR?R?—NR??)n— where R?, R?, R?? are identical or different and independently represent hydrogen or an optionally substituted alkyl radical, aryl radical, vinyl radical or (trialkoxysilyl)alkyl radical, n being an integer and or being calculated such that the polysilazane has a number-average molecular weight of from 150 to 150 000 g/mol, and b) a catalyst in an organic solvent, removing the solvent using evaporation such that a polysilazane layer having a layer thickness of 0.05-3.0 ?m remains on the substrate, and irradiating the polysilazane layer with VUV radiation having wavelength portions <230 nm and UV radiation having wavelength portions between 230 and 300 nm in an atmosphere containing steam in the presence of oxygen, active oxygen and optional nitrogen.