We describe the preparation, electrochemical and structural properties of the thin film Y-stabilized ZrO 2 (YSZ), of interest for solid oxide fuel cell (SOFC) at an operating temperature of 800°C. Thin films of YSZ were prepared by reactive sputtering deposition of Zr–Y targets in Ar–O 2 mixture atmospheres. The thickness of the YSZ film, deposited onto the porous NiO–YSZ substrates, is approximately 8 μm. The microstructure of the YSZ film was investigated using scanning electron microscope. The electrochemical properties of a thin film cell Ag/NiO–YSZ/YSZ/Ag were studied using impedance spectroscopy. The electrolyte and electrode (substrate) resistances were measured under different atmospheres as a function of temperature. Above 600°C the ohmic resistance of the cermet electrode (substrate) is comparable to the ionic resistance of the solid electrolyte. This is probably influenced by the cermet electrode microstructure.