Fuel cells are recently developed in all kinds of fields from the viewpoint of effective energy utilization and environmental protection. Especially, Polymer Electrolyte Fuel Cell (PEFC) is expected to be effective power resources of the next generation car. It is important for the improvement of performance to precisely estimate the gas flow through the PEFC. In the present paper, gas flow fields were numerically calculated by lattice gas automata method. It was clarified that lattice gas automata analyses with consideration of channel height were useful for good estimation of gas flow through the PEFC. It was concluded that the lattice gas automata method could be the powerful tool for design the PEFC.