Patent ID: 8304140

Claim:
A fuel cell formed by stacking a membrane electrode assembly and a metal separator in a form of a corrugated plate in a stacking direction, the membrane electrode assembly including a pair of electrodes and an electrolyte interposed between the electrodes, a first fluid flow field and a buffer as a passage for one of a fuel gas, an oxygen-containing gas and a coolant being formed on one surface of the metal separator, a second fluid flow field and a buffer as a passage for another one of the fuel gas, the oxygen-containing gas and the coolant being formed on an opposed surface of the metal separator, the metal separator comprising first and second metal separators, the membrane electrode assembly being sandwiched between the first and second metal separators or the first and second metal separators directly contacting each other, wherein the first metal separator has a plurality of rows of bosses protruding toward the second metal separator in the buffer and a plurality of continuous guide ridges, wherein the plurality of rows of bosses and the plurality of continuous guide ridges are alternately arranged on the separator; the second metal separator has a plurality of continuous guide ridges protruding toward the first metal separator in the buffer and a plurality of rows of bosses, wherein the plurality of rows of bosses and the plurality of continuous guide ridges are alternately arranged on the separator; and wherein the plurality of rows of bosses and the plurality of continuous guide ridges are provided at positions overlapped with each other in the stacking direction.