METHOD FOR CLEANING OPTICAL DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method for cleaning not only a SiO2-based optical device but also a CaF2-based optical device by removing organic matters adsorbed on the surface of each of the optical devices and to provide a method for cleaning the optical device having even an optical thin film such as a reflection preventing film. SOLUTION: This method for cleaning the optical device comprises at least a step to clean the optical device with an organic solvent, a step to clean the optical device by irradiating it with ultraviolet rays in an oxygen-containing atmosphere and a step to clean the optical device by heating it.