The reactant distribution in a gas diffusion layer adjacent the landings of a solid polymer electrolyte fuel cell can be improved by using a flow field plate in which suitable sequential protrusions have been incorporated in the channels. The reactant flow field in the plate comprises a plurality of parallel channels in which protrusions are arranged in a sequence along each channel's length and the sequential protrusions in any given channel are offset with respect to the sequential protrusions in the channels immediately adjacent thereto.