Electrochemical properties (terminal voltage, ohmic resistance and overpotential) were measured for the cell of indium tin oxide cathode (ITO, 90 mass% In2O3-10 mass% SnO2) or perovskite-type oxide cathode La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) / Gd-doped ceria electrolyte (Ce0.8Gd0.2O1.9, GDC, 600-700 mu m thick)/Ni-GDC anode using 3 vol% H2O-containing H-2 fuel at 873 and 1073 K. The maximum power densities for the cell with ITO cathode at 873 and 1073 K were 21 and 71 mW/cm(2), respectively. Similarly, the maximum power density with LSCF was 12 and 113 mW/cM(2) at 873 and 1073 K, respectively. The voltage drop was larger for the cathode than for the electrolyte or anode. The overpotential of the LSCF cathode was comparable to the ohmic resistance.