SOFCs are expected to become competitive devices for electrical power generation, but successful application is dependent on reducing the working temperature from 1000 to 800 degreesC, without detrimental effects on resistance and on electrode processes. This requires a reduction of the stabilized zirconia electrolyte thickness and an optimization of the electrodes and interfaces. We have studied the preparation of thin film SOFC devices working at intermediate temperature (< 850C). Ni/YSZ cermet anodes were prepared by a conventional ceramic method and support the cells. Thin yttria stabilized zirconia electrolytes (YSZ) and thin La0.7Sr0.3MnO3 (LSM) cathodes were deposited by a spray method onto a Ni/YSZ cermet. Complete cells have been tested under humidified hydrogen and methane at 850 degreesC. (C) 2000 Elsevier Science B.V. All rights reserved.