ULTRAVIOLET STERILIZING APPARATUS

PROBLEM TO BE SOLVED: To certainly detect the contamination degree of a sterilizing lamp to perform washing without delaying washing timing and to prevent the adverse effect of treated water used in washing on environment. SOLUTION: An expanded cylindrical part 19 for allowing treated water to overflow an upper open port 17 of which the flow channel cross-sectional area larger than that of a sterilizing cylinder 15 is provided to the upper part of the sterilizing cylinder 15 long up and down and at least a plurality of sterilizing lamps 23 and a contamination detection sensor 25 for detecting the contamination of the sterilizing lamps 23, air diffusion nozzles 27 blowing off compressed air toward the sterilizing lamps 23 are provided in the sterilizing cylinder 15.