A method for coating a separator for a fuel cell is provided that includes vaporizing a metal carbide precursor to obtain a precursor gas; introducing a metal carbide coating layer-forming gas including the precursor gas in a reaction chamber; and applying a voltage to the reaction chamber so that the precursor gas is changed into a plasma state, thereby forming a metal carbide coating layer on either surface or both surfaces of a substrate. In this case, the metal carbide precursor may include a compound having a substituted or non-substituted cyclopentadienyl group.