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 • γ1 and (Equation 2): PT • y2 = P02 • x2 • γ2, 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.
