NOVELTY - The metal separator (10) has a metal coated portion (12) covered on main component portion (13) formed using a metal plate material containing main component alloy of nickel, chromium, molybdenum, copper, titanium, iron, and carbon and sulfur as impurity. Sum total content of Ni, Cr, Mo, Cu and Ti in the alloy is 48.1 mass% or more. Portion (13) has thickness of 1-500 nm and consists of noble metal.    USE - For fuel cell (claimed) such as polymer electrolyte fuel cell, phosphoric acid fuel cell, solid electrolyte fuel cell and molten carbonate fuel cell, mounted on electric vehicle.    ADVANTAGE - The metal separator has favorable corrosion resistance of main component alloy, contact resistance with cell main component, and hot working property, without generation of inter-crystalline crack in main component portion during processing. Elution of main component alloy from exposure surface by corrosion, and time dependent increase in battery internal resistance are suppressed. Outflow of gas by crack connecting to gas passageway is prevented. Segregation of impurity such as sulfur on grain boundary of main component alloy is prevented.    DETAILED DESCRIPTION - The metal separator (10) has a metal coated portion (12) covered on a main component portion (13) formed using a metal plate material containing a main component alloy of nickel (Ni) (in mass%) (30-82), chromium (Cr) (15-30), molybdenum (Mo) (2-4), copper (Cu) (1-4), titanium (Ti) (0.1-3), iron (51.9 or less and including 0), and carbon and sulfur as impurity. Sum total content of Ni, Cr, Mo, Cu and Ti in the alloy is 48.1 mass% or more. Sum total content of impurity is 0.0001 mass% or more, preferably 0.001-1 mass%. Portion (13) has thickness of 1-500 nm and consists of noble metal. A gas passageway is formed between electrode layers, by laminating plate material on electrode layer, which covers the solid polymer electrolyte film of fuel cell. The metal coated portion comprises gold, silver, platinum, ruthenium or palladium as main component.    INDEPENDENT CLAIMS are included for the following:    (1) manufacture of metal separator; and    (2) fuel cell.    DESCRIPTION OF DRAWING(S) - The figure shows an enlarged and partial cross-sectional view of metal separator used for fuel cell.    metal separator (10)    metal coated portion (12)    main component portion (13)    convex portion (20)    concave portion (21)