NOVELTY - The fuel cell has a hydrogen pole separator (8) equipped with a nitrided layer (I) containing transition-metal nitride of a metal nitride crystal structure which is continuously formed on a surface nitriding treatment portion of base material (A) containing molybdenum, and an oxygen electrode separator (9). The oxygen electrode separator is equipped with a nitrided layer (II) containing transition-metal nitride of metal nitride crystal structure which is continuously formed on a surface nitriding treatment portion of base material (B) containing chromium (20 wt.% or more).    USE - Fuel cell is used for fuel-cell vehicle (claimed) and motor vehicles.    ADVANTAGE - The fuel cell has excellent durability and electric power generation performance. The fuel cell is economical.    DETAILED DESCRIPTION - The fuel cell has a hydrogen pole separator and an oxygen electrode separator. The hydrogen pole separator is equipped with a nitrided layer (I) containing transition-metal nitride with a metal nitride (M4N) crystal structure which is continuously formed on a surface nitriding treatment portion of base material (A) containing molybdenum. The oxygen electrode separator is equipped with a nitrided layer (II) containing transition-metal nitride with a metal nitride (M4N) crystal structure which is continuously formed on a surface nitriding treatment portion of base material (B) containing chromium (20 wt.% or more). The transition-metal atom is iron, chromium, nickel or molybdenum. The base material (A) is SUS316L and base material (B) is SUS310S. An INDEPENDENT CLAIM is included for manufacture of fuel cell.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional drawing of the structure having arranged the hydrogen pole separator and oxygen electrode separator on both sides of the single cell comprising a fuel cell stack.    Single cell (2)    Solid polymer-type electrolyte film (3)    Catalyst layer (6)    Hydrogen pole separator (8)    Oxygen electrode separator (9)