STERILIZER

PROBLEM TO BE SOLVED : To provide a sterilizer constituted so as to suppress a rise in surface temperature and capable of ensuring the starting properties of an electrodeless valve. SOLUTION : The sterilizer is used in the case of a microwave generator for generating microwaves with a predetermined wavelength λ and equipped with at least one electrodeless valve 2 for housing a substance receiving the energy of microwaves to emit ultraviolet rays and a rear gas. This sterilizer is equipped with a starting assist valve 3 irradiated with microwaves and receiving the energy of microwaves to generate discharge in the valve. A metal film is formed to the inner surface of the starting assist valve 3 and the starting assist valve 3 has at least a rare gas, which is the same to the rare gas sealed in the electrodeless valve 2, sealed therein and is formed from a material transmitting the radiant light of the discharge generated in the starting assist valve 3 to the outside.