Power generation with direct methanol fuel cell (DMFC) systems requires only simple equipment, and has the important advantage of using a liquid fuel with higher energy density and easier handling characteristics than hydrogen. However, the power output of DMFC is lower than hydrogen fuel cells. To improve the power output of DMFC it is very important to reduce diffusion polarization at higher current density conditions. This research used a corrosion-resisting type porous stainless steel developed based on the technology for metal-hydride battery electrodes in the separator flow fields for reactants and products in a single cell DMFC and analyzed its influence on performance characteristics. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.