We designed and constructed a pressurized 5 kW anode-supported planar solid oxide fuel cell (SOFC) power generation system with a pre-reformer for a fuel cell/gas turbine hybrid system. The 5 kW class SOFC stack, which was made by Forschungszentrum Julich (FZJ) in Germany, was assembled and installed at KIER. We also investigated the stack's typical operating characteristics, particularly with respect to the thermal cycling test, the fuel change from H-2 to pre-reformed gas, and the pressurized operation at 3.5 atm (abs.) under hybrid operating conditions with a micro-gas turbine. In atmospheric pressure, the output of the SOFC stack was 8.1 kW for the H2 and 4.7 kW for the pre-reformed gas. When the stack with an liquefied natural gas (LNG) pre-reformer was operated in combination with a micro-gas turbine, the stack showed an output of 5.1 kW at 3.5 atm (abs.). From the experimental results, we conclude that the anode-supported planar SOFC stack operates successfully in a pressurized hybrid system with a micro-gas turbine. We also established a unique procedure and a basic technology in which the anode-supported planar SOFC stack could be operated under pressurized conditions in combination with a pre-reformer. Moreover, we achieved successful operation of a hybrid system that combines an SOFC power system with a micro-gas turbine. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.