A 2D computational fluid dynamics (CFD) model is developed to study the performance of an advanced planar solid oxide fuel cell based on proton conducting electrolyte (SOFC-H). The governing equations are solved with the finite volume method (FVM). Simulations are conducted to understand the transport phenomena and electrochemical reaction involved in SOFC-H operation as well as the effects of operating/structural parameters on SOFC-H performance. In an SOFC based on oxygen ion conducting electrolyte (SOFC-O), mass is transferred from the cathode side to the anode side. While in an SOFC-H, mass is transferred from the anode to the cathode, which causes different velocity fields of the fuel and oxidant gas channels and influences the distributions of temperature and gas composition in the cell. It is also found that increasing the inlet gas velocity leads to an increase in the local current density and a slight decrease in the SOFC-H temperature due to stronger cooling effect of the gas species at a higher velocity. Another finding is that the electrode structure does not significantly affect the heat and mass transfer in an SOFC-H at typical operating voltages. Copyright (c) 2009 John Wiley & Sons, Ltd.