To provide a heat-treating furnace and a heat-treating method that can miniaturize an exhaust gas recovery apparatus, can improve the capacity of the heat-treating furnace as compared with before, and can also cope with environmental problems.

The heat-treating furnace comprises: a heating furnace body 12 that is divided from the periphery for preventing air from entering; and a burner 13 that is mounted to the heating furnace body 12 for allowing hydrogen and oxygen gases to be subjected to a combustion reaction. Since a raw material introduced into the heating furnace body 12 is heated by high-temperature steam generated by the burner 13, the generation of by-products such as carbon dioxide other than vapor can be prevented, which differs from a case for using for example LPG, kerosene, heavy oil, or the like. Additionally, the exhaust gas recovery apparatus can be miniaturized and a possibility for causing environmental problems can be drastically reduced.