PROBLEM TO BE SOLVED: To prevent condensation of hydrogen peroxide gas in a decontamination object chamber in decontamination that uses the hydrogen peroxide gas as decontamination gas.SOLUTION: A yield of hydrogen peroxide gas G in a gas evolution means 1 is regulated, a hydrogen peroxide gas concentration c of a decontamination object chamber 5 is regulated to a target concentration cm, base on measurement absolute humidity x of the decontamination object chamber 5 and the target concentration cm, a condensation temperature td of the hydrogen peroxide gas G in the decontamination object chamber 5 in a state of the measurement absolute humidity state x and in a state in which the hydrogen peroxide gas concentration c is the target concentration cm is calculated, and a temperature t of the decontamination object chamber 5 is regulated to a temperature tm that is higher than a calculated condensation temperature td (tm>td) by regulating heat output of a heating means 6 based on the calculated condensation temperature td.COPYRIGHT: (C)2014,JPO&INPIT【課題】除染ガスとして過酸化水素ガスを用いる除染において、除染対象室での過酸化水素ガスの凝縮を防止する。【解決手段】ガス発生手段1での過酸化水素ガスGの発生量を調整して除染対象室5における過酸化水素ガス濃度cを目標濃度cmに調整するとともに、除染対象室5の計測絶対湿度xと目標濃度cmとに基づき、計測絶対湿度状態xでかつ過酸化水素ガス濃度cが目標濃度cmである状態での除染対象室5における過酸化水素ガスGの凝縮温度tdを演算して、その演算凝縮温度tdに基づき加熱手段6の加熱出力を調整することで、除染対象室5の温度tを演算凝縮温度tdより高い温度tmに調整する(tm>td)。【選択図】図1
