Abstract: A heating furnace includes: a heating furnace main body that includes an accommodation chamber capable of accommodating a heating target object; a heat source capable of heating an inside of the accommodation chamber to an annealing point; a gas supply source that is arranged outside the heating furnace main body; and a pipeline that includes a pipeline main body that is arranged inside the accommodation chamber, and that is heated by the heat source, the pipeline main body being configured to retain a gas supplied from the gas supply source and heat the gas to the annealing point, and a discharge outlet that is formed on an end portion of the pipeline main body, and that is opened inside the accommodation chamber, the discharge outlet being configured to discharge the gas that is heated to the annealing point, to the inside of the accommodation chamber.

Abstract: A method for manufacturing an optical element includes floating an optical element material in gas to heat the optical element material, and thereafter making first and second shaping molds contact the floating optical element material at the same time, and pressurizing the optical element material by using the first and second shaping molds.