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, the method including: heating an optical element material by suspending it in a gas; supplying the heated optical element material from a direction which intersects a central axis interconnecting centers of a first mold and a second mold to a space between molds in a non-contact state, the space between molds being a space between the first mold and the second mold; pressurizing the optical element material supplied to the space between molds by the first mold and the second mold; and cooling the pressurized optical element material.

Abstract: An apparatus for manufacturing a glass optical element includes: a heating unit that heats a glass material; a pressurizing unit that pressurizes the glass material; a cooling unit that cools the glass material; a molding room in which the heating unit, the pressurizing unit, and the cooling unit are located; an inert-gas supplying unit that forms a plurality of flows of an inert gas within the molding room by blowing the inert gas in a plurality of directions crossing each other; and an inert-gas emitting unit that emits, from within the molding room, the inert gas supplied into the molding room by the inert-gas supplying unit.

Abstract: An apparatus for manufacturing a glass optical element includes: a heating unit that heats a glass material; a pressurizing unit that pressurizes the glass material; a cooling unit that cools the glass material; a molding room in which the heating unit, the pressurizing unit, and the cooling unit are located; an inert-gas supplying unit that forms a plurality of flows of an inert gas within the molding room by blowing the inert gas in a plurality of directions crossing each other; and an inert-gas emitting unit that emits, from within the molding room, the inert gas supplied into the molding room by the inert-gas supplying unit.

Abstract: A method for manufacturing an optical element, the method including: heating an optical element material by suspending it in a gas; supplying the heated optical element material from a direction which intersects a central axis interconnecting centers of a first mold and a second mold to a space between molds in a non-contact state, the space between molds being a space between the first mold and the second mold; pressurizing the optical element material supplied to the space between molds by the first mold and the second mold; and cooling the pressurized optical element material.