Electrostatic Precipitators (ESP) are used extensively for decontaminating of industrial gaseous pollution and air cleaning of building. One application of the ESP is decontaminating polluted gases and increasing the visibility index in expressway tunnels. However, the collection efficiency of large particle decreases due to particle re-entrainment phenomena, since lots of particles in expressway tunnels are made of carbon that has low resistivity. Therefore, large particle has the adverse effect of decreasing visibility index. It is important to prevent re-entrainment for increasing the visibility index. In this work, we discussed the method preventing particle re-entrainment, and devised applying rectangular AC high voltage to the collecting electrodes. DC voltage is applied to precharger in all test conditions. The collection efficiency of large particle decreases due to particle re-entrainment with DC high voltage applied to electrode in collecting section. However, when rectangular AC high voltage applied to the collecting electrodes, the collection efficiency of large particles improves with increasing frequency. The re-entrainment phenomena are prevented on applying rectangular AC high voltage (1Hz). And then, the collection efficiency of submicron particles on applying rectangular AC high voltage (1Hz) is as high as DC high voltage.