A separator for a fuel cell is provided. The separator is disposed at both sides of a membrane-electrode assembly and is configured to supply a reaction gas to the membrane-electrode assembly. In addition, the separator includes a conductive microporous body that is formed on a reaction surface corresponding to the membrane-electrode assembly and a channel unit that is connected to an inlet manifold and an outlet manifold through which the reaction gas flows and is configured to guide the reaction gas to the reaction surface.