A computational fluid dynamics model is developed to study the steady-state behavior of a microtubular solid oxide fuel cell (SOFC). The model incorporates mass, momentum, species, and heat balances along with ionic and electronic charge transfers. The anode-supported SOFC studied in this work consists of a ceria-based electrolyte which is known as an electronic conductor in reducing atmospheres, letting electrons leak through the electrolyte. Related internal leakage currents are calculated implicitly in the model to incorporate the performance losses. Moreover, to have a more realistic approach while cutting down the computational effort, in this study a fuel cell test furnace is also modeled separately to evaluate the distribution of the oxygen concentration and temperature field inside the furnace. Results from the furnace model are used as boundary conditions for the fuel cell model. Fuel cell model results are compared with the experimental data which shows good agreement. (c) 2008 The Electrochemical Society.