Abstract: The present invention relates to a method of uniformly induction heating a metallic elongated material having different thickness sections seen in the longitudinal direction, and more particularly relates to a method of ensuring substantially uniform heating for a metallic elongated material over the whole length thereof irrespective of the existence of different thickness of diameter section(s). Specifically, an inductor for practicing the method of the invention is constructed in the form of a multi-turn coil which is adapted to be separated to a certain number of coil segments corresponding to the geometrical configuration of the metallic elongated material. Uniform distribution of temperature over the metallic elongated material is achieved by properly program controlling power supply to the respective turns of the coil and thereby controlling a heating time thereof, while the inductor itself is maintained as fixed.