To provide a cylindrical metallic heating furnace using three combustion burners with high thermal efficiency.

The cylindrical metallic heating furnace having the combustion burners for burning fuel gas in a cylindrical furnace 16 includes the three combustion burners as the first combustion burner 13, the second combustion burner 14 and the third combustion burner 15. Since the three combustion burners 13, 14 and 15 are arranged so as to generate flames in the same direction relative to the furnace 16, the flows of combustion gas generated in the respective combustion burners do not interfere with each other. Accordingly, the gas flows can circulate on the periphery of a material 12 to be heated while they maintain their high speed, so that the material 12 to be heated can be uniformly and efficiently heated.