A fuel cell is provided therein with a metal separator for aiming at preventing corrosion and at reducing a contact resistance. The separator is compose of conductive passage board formed therein with passages, and a metal planar panel, the passage boards and the metal planar panel being superposed with one another. The metal planar panel is formed therein with a plurality of manifolds for passing reactive gas or cooling medium through an adjacent cell while the passage boards are formed therein with a plurality of meandering through channels for distributing the reactive gas or the cooling medium from the manifolds. Further, a part of the meandering through channels is superposed with a part or all parts of the manifolds, and a covering layer for preventing the metal planar panel from being corroded, and for restraining a growth of a nonconductive film is formed over an entire part of the metal planar panel or over at least a part thereof which makes contact with the meandering through channels.