To provide a heating apparatus to efficiently, uniformly and safely heat a cylindrical metallic coil in a short time.

An iron core 2 is passed through an inner surface of the cylindrical metallic coil 1 formed by winding a strip-like metal so that the surface thereof is insulated, an iron core 3 is provided on an outer portion of the cylindrical metallic coil 1 so that a ring-like magnetic circuit is formed with the core 2, and a primary coil 4 is wound around the core 3 to connect a primary power source thereto. On the other hand, the outside and the inside of the cylindrical metallic coil 1 formed of the strip-like metal are short-circuited by electrodes 6, 7 connected via an electrically conductive member 5 to form a secondary circuit. A transformer is formed, and the voltage is applied to the primary coil 4 to allow the current run in the coil 1 formed of the strip-like metal to perform the heating. By using a container which surrounds the cylindrical metallic coil 1, forms no electrically secondary circuit and has a heat insulation layer to introduce the atmospheric adjusting gas and a heater for temperature compensation, even the cylindrical metallic coil with the differential temperature can be uniformly heated in a short time while adjusting the atmosphere.