It is determined that indoor condensation of hydrogen peroxide vapor is to occur, if there is a solution with which both (Equation 1): PT €¢ y1 = P01 €¢ x1 €¢ ³1 and (Equation 2): PT €¢ y2 = P02 €¢ x2 €¢ ³2, which indicate vapor-liquid equilibrium, hold. With this, it is possible to accurately determine whether indoor condensation of hydrogen peroxide vapor is to occur or not in decontamination.當存在有代表氣液平衡之下述(式1)、(式2)PT．y1=P01．x1．γ1.........(式1) PT．y2=P02．x2．γ2.........(式2)均為成立之解的狀態時，判定係產生有過氧化氫蒸氣之室內凝縮。藉由此，而對於在除污染中是否產生有過氧化氫蒸氣之室內凝縮一事作正確的判定。
