Destruction and removal efficiency (DRE) of SF6 was tested with low degrees of ionization. The applied dose of ionization energy varied from 63.70 to 212.34 kGy. The initial concentration and flow rate of SF6 gas were 1,000 ppm and 50L/min, respectively. In order to increase the DRE, injection of conditioning agent (H2) were conducted. The DRE of SF6 increased about 2 times with injection of H2 gas.