This work aims to construct the hydrogen-air fuel cells, which operate at intermediate temperature. In order to reduce the operation temperature, the fuel cells are constructed from a thin proton conducting oxide electrolyte and a hydrogen-permeable membrane anode. In this work, we examine at first the applicability of the hydrogen-permeable metal membrane for the anode in the fuel cell. Then, we evaluated the performance of the fuel cells consisting of the thin electrolyte supported by the metal membrane anode.It is recognized that the hydrogen-permeable metal membrane anode works well similar to the porous Ni anode except the voltage loss. The voltage loss for the fuel cell with the Pd anode is lower than that for the fuel cell with the porous Ni anode.BaCe0.9Y0.1O2.95 films, which are used for the electrolyte in the fuel cells, are prepared by the pulsed laser ablation method on the hydrogen-permeable metal substrates used as the anode. The fuel cells with the BaCe0.9Y0.1O2.95 electrolyte of 1.5-2.0 pin thickness and the hydrogen-permeable Pd anode of 25 mum thickness operate stably giving an open circuit voltage of 0.86 V at 400degreesC and the power density of 0.52 mW/cm(2) is derived. (C) 2003 Elsevier B.V. All rights reserved.