The effects of cell configuration, materials, assembly method, and temperature control method on the performance of Japan Automobile Research Institute's (JARI's) standard single cell were investigated in order to reproducibly estimate the influence of impurities. From the results, active electrode area, flow channel configuration, clamping torque, and thermal design of the cell were optimized. JARI's standard single cells are used for investigating hydrogen fuel, because they are easily assembled and disassembled, have uniform electric generation performance from one unit to another, and have high reproducibility from one test to another. (c) 2005 Elsevier B.V. All rights reserved.