In this study, yttrium-stabilized zirconia (YSZ) thin films 1-2 mm thick electrolyte have been prepared using NiO-YSZ anode as substrates. Fuel cell test was conducted with the single chamber configuration in methane-air gas mixture using (La,Sr)(Co,Fe)O-3 (LSCF) as the cathode. Test results showed that the open-circuit voltage to be >0.8 V, with power density as high as 0.12 W cm(-2). It was also shown that gas flow rate has a large influence on the performance of the fuel cell, which indicates the importance of the geometrical design for anode support fuel cell system. (C) 2004 The Electrochemical Society.