One of the most important innovations in solid oxide fuel cells is to have a membrane-like cell unit and to use a thin and dense electrolyte with reduced internal resistance. This paper deals with thin yttrium-stabilized zirconium oxide layers. An experimental study is carried out on vacuum-sprayed zirconium dioxide-8wt% yttrium oxide layers. The investigation of the process showed that layers of low porosity were obtained with a fine powder and an optimized plasma gas composition. Increased He flow, spray performance, and short spacing resulted in lower porosity and surface roughness. With optimized spraying conditions, thin YSZ layers with a thickness of 10-20 gm, lesser than 1% porosity, and an average roughness of 1 gm are achieved. Paper includes a German-language abstract.