PURPOSE: To uniformly heat a billet while effectively preventing the overheating of its both ends by providing plural axial burners in parallel on the wall surface of the nose part of the billet heating furnace in a skid group and a side burner on both side wall surfaces and separately controlling the combustion of the burners.

CONSTITUTION: The inside of a furnace casing 1 is separated by a nose part 2 into plural zones 3-5, and the axial burner 6, roof burner 7, etc., for blowing off a combustion flame are arranged in the zones. A billet 8 to be treated is transferred in the casing 1 by a transfer mechanism 9 toward the axial outlet 11 from an inlet 10. In this billet heating furnace, the mechanism 9 consists of the moving support 15 of a moving beam 14 and a fixed support 16, and the billet is supported by the skid buttons 13 on horizontal skids 12. Plural axial burners 20 are provided in parallel on the wall surface of the nose part 2 at the intermediate position in the cross direction of the furnace in the skid 12 group, and a side burner 21 is furnished on both side wall surfaces of the casing 1. The fuel supplies to the burners 20 and 21 are separately controlled based on the temps. of the intermediate part in the cross direction of the furnace and the furnace temps. on both sides to uniformly heat the billet 8.