CLEANING AGENT FOR HARMFUL GAS CONTAINING SILICON CHLORIDE AND CLEANING METHOD THEREOF

PROBLEM TO BE SOLVED: To attain high cleaning performance even when the concentration of silicon chloride contained in a gas to be treated is low and the gas to be treated is dried by using cupric oxide, manganese dioxide having a BET specific surface area equal to or above a specific value and the hydroxide of an alkali metal as effective components. SOLUTION: This cupric oxide has preferably >=10 m2/g BET specific surface area, more preferably 50-100 m2/g. The manganese dioxide has usually >=130 m2/g BET specific surface area (high specific surface area manganese dioxide), preferably about >=175 m2/g. As the hydroxide of the alkali metal, potassium hydroxide is preferably used alone in the view point of excellent cleaning performance. As the radio by weight of the cleaning agent in the effective component, the cupric dioxide is 25-98%, the high specific surface area manganese dioxide is 1-60% and the hydroxide of the alkali metal is 1-15%.