Abstract: Provided is a method of producing an optical element. The method includes heating a preform that is made of a fluorophosphate glass material to alter a region including a surface of the preform to form a protection layer; and performing press molding on the preform with the formed protection to form a molded object having an optical element shape.

Abstract: A method of producing an optical element includes: determining, as a reference mold set, a first mold set from among mold sets; determining a set temperature for the reference mold set; acquiring reference data by measuring, by a temperature measurement sensor, a temperature of the reference mold set; measuring, by the temperature measurement sensor, a temperature of a second mold set that is at least one of the mold sets other than the reference mold set; calculating a correction value based on a measurement result obtained by the measuring and on the reference data; determining a set temperature for the second mold set based on the set temperature for the reference mold set and on the correction value; and performing temperature control on the mold sets based on set temperatures determined for the respective mold sets to produce the optical elements.