The performance of anode-supported tubular solid oxide fuel cells (SOFCs) was investigated in terms of the thickness of the anode support. Considering the geometry of single cell, it can be readily known that the concentration polarization across the anode-support is the most significant factor in determining the performance of the cell. For this purpose, we fabricated single cells having different anode-support thicknesses of 1 mm and 2 mm. Both the cathode layer ((La0 85Sr0 15)0 98MnO 3) and electrolyte layer (8 mol%yttriastabilized zirconia) were coated at the same condition. The cell performance increased with decreasing anode-support wall thickness. The single cell with a 1 -mm-thick wall showed a power density of 0.42 m W/cm2 at 0.7 V and 700°C From the analysis of impedance spectra, it was concluded that the total polarization of the anode-supported tubular SOFC was mainly governed by the concentration polarization caused by the mass transport though the anode support.