METHOD FOR HEATING MATERIAL TO BE HEATED

PROBLEM TO BE SOLVED: To provide a method for heating a material to be heated which enables more efficient gradient heating of the material to be heated by controlling temperature distribution in the furnace width direction using a regenerative burner.SOLUTION: Alternating combustion is performed by alternately switching combustion and exhaust between regenerative burners 12A and 12B (12C and 12D), each of which is opposed to each other in the furnace width direction such that combustion flames Fr, each of which is opposed to each other, are formed between the regenerative burners (12A and 12C) and (12B and 12D), each of which is adjacent to each other in the furnace length direction of a soaking area. Also, while the regenerative burners on the exhaust side perform heat accumulation-collection of exhaust heat from combustion exhaust gas by heat reservoirs, the regenerative burners on the combustion side preheat combustion air by the heat reserved in the heat reservoirs. Furthermore, gradient heating is performed by setting a gradient in temperature distribution in the furnace width direction of the soaking area by setting combustion amounts different from each other between regenerative burners 12A and 12C arranged on one side in the furnace width direction of the soaking area and regenerative burners 12B and 12D arranged on the other side.