PURPOSE: To safely and efficiently remove a gaseous silicone compound as a noxious component, by contacting the gas containing the gaseous silicon compound with a specific removing agent.

CONSTITUTION: CuO (a), Al2O3 (b) and/or SiO2 are mixed and the resulting mixture is subsequently kneaded by a kneader and, after drying, molded into a pellet to obtain a removing agent. A cylinder is packed with this removing agent to form a usual fixed bed and gas containing a gaseous silicon compound represented by formula (wherein X is halogen, n is 1 or 2 and m is 0W4) as a noxious component is contacted with said fixed bed to perform dry absorbing treatment. A contact temp. is pref. 0W150°C. Further, the ratio of the components (a), (b) is pref. 0.02W7 on the basis of the atomic ratio M/(M+Cu) (wherein Cu is the atomic number of copper and M is the total number of atomic number of Al and/or Si) of metals.