An EGR system is configured to allow a part of exhaust gas discharged from an engine to an intake passage to flow as EGR gas to an intake passage through an EGR passage to return to the engine. In the EGR system, a heating film is provided on an inner wall or an outer wall of at least one of the intake passage through which the EGR gas is allowed to flow and the EGR passage. At least a pair of a positive electrode and a negative electrode is provided to energize the heating film.