A fuel cell includes a membrane electrode assembly including an electrolyte membrane and catalyst layers joined on both sides of the electrolyte membrane and a pair of separators disposed at both sides of the membrane electrode assembly to respectively form gas flow spaces where two types of power generation gases flow. An electrically conductive porous substrate folded in a corrugated shape is disposed in at least one of the gas flow spaces defined on both sides of the membrane electrode assembly, and a gas flow space in which the electrically conductive porous substrate is disposed is divided into a plurality of gas flow paths substantially parallel to a flow direction of the power generation gases.