Patent ID: 6921600

Claim:
A separator for a fuel cell, the fuel cell having two separators and a membrane electrode assembly being sandwiched by the two separators, the membrane electrode assembly being provided with an anode electrode, a cathode electrode and an electrolytic membrane sandwiched by the two electrodes, each of the two electrodes having a diffusion layer allowing diffusion of one of a gaseous oxidizing agent and fuel gas; the separator comprising: a plate-like member; and a plurality of projections for forming a plurality of gas passages which allow flow of one of the gaseous oxidizing agent and fuel gas, the projections being provided on the plate-like member and making contact with the membrane electrode assembly, one of the gas passages being defined by two adjacent projections, the plate-like member and the membrane electrode assembly; wherein a coefficient of thermal conductivity of the projection is smaller than a coefficient of thermal conductivity of the plate-like member of the separator; and wherein in the projections, the coefficient of thermal conductivity in a direction of a depth of the projection is smaller than the coefficient of thermal conductivity in a direction orthogonal to the depth.