METHOD OF PURIFYING WASTE GAS

PROBLEM TO BE SOLVED: To provide a method of purifying a waste gas discharged from a semiconductor production equipment and containing nitrogen oxides and/or an organic solvent at a high concentration with a large concentration fluctuation, at a relatively low temperature with a high decomposition rate without using a large-scale purifying apparatus or a complicatedly structured purifying apparatus. SOLUTION: The waste gas is purified by bringing the waste gas containing the nitrogen oxides and/or the organic solvent into contact with a purifying agent containing a metal or a metal oxide as effective ingredients or a purifying agent containing a low-order metal oxide and a high-order metal oxide as effective ingredient to carry out the reduction of the nitrogen oxide and/or the oxidation decomposition of the organic solvent under heating, detecting the increase and decrease or the deviation of the purifying agent components by the oxidation reduction reaction, and supplying a correction gas when the composition ratio of the purifying agent components deviates from the control range of the component ratio of the purifying agent components while recovering the composition ratio. COPYRIGHT: (C)2004,JPO