Reactive species play important roles in surface treatments using plasma. However, the effect of each type of reactive species on surface treatments is difficult to measure because plasma simultaneously produces many types of reactive species. To examine the effect of each type of reactive species on surface treatments, vacuum ultraviolet (VUV) photolysis method was developed in our previous works. VUV light irradiates an Ar/H2O/O-2 mixture flowing in a quartz tube to produce a limited number of different types of reactive species by photolyzing the H2O and O-2. These reactive species are then supplied to a surface in ambient air. A simulation of the VUV method was developed previously for calculating the densities of reactive species. However, the simulation has not yet been sufficiently verified. In this work, the simulation of the VUV method was verified by comparing the simulated and measured densities of OH, O-3, H2O2, H-2, and O-2(a(1)Delta(g)). The results showed that the simulation calculates the densities of those reactive species well, indicating the validity of the simulation.