Abstract: In order to create a regenerative, energy-saving fuel firing for an industrial furnace, particularly for a metal smelting furnace, that can flexibly take all possible time and space operating conditions and demands of the furnace to be heated as well as the thermic conditions of the respectively employed, heat-storing regenerators exactly into consideration, it is inventively proposed that at least two regenerator/burner modules (3) are switchable from burner mode (7) into regenerator mode (7r) (exhaust gas extraction mode) or, respectively, vice versa independently of one another proceeding from the process controller of the industrial furnace (1), namely with employment of reverse valves (11) or reversible ventilators or, respectively, two-stream ventilators.