Patent ID: 7364814

Claim:
A separator of a fuel cell comprising: a base material made of metal; and a surface treatment layer formed on said base material, said surface treatment layer including: a base material-side portion made from metal or semi-metal, or a carbide of said metal or semi-metal; and a base material opposite-side portion (i) including an outermost layer constant in composition concentration and (ii) made from carbon formed at an atom level, or composite materials of carbon and (a) said metal or semi-metal or (b) said carbide of said metal or semi-metal formed at an atom level, wherein said surface treatment layer includes at least two of said metal or semi-metal, said carbide of said metal or semi-metal, and carbon, and a portion of said surface treatment layer except said outermost layer inclines in concentration between said base material-side and said base material opposite-side and a composition ratio of said carbon in said portion of said surface treatment layer except said outermost layer is increased in a direction away from said base material.