A DC corona discharge reactor was applied to remove sulfur dioxide (SO2) and benzene (C6H6) from N-2-O-2-H2O mixed gas in the temperature range from room temperature to 400 degreesC. When SO2 was removed, the temperature elevation caused the decrease of the removal efficiency of SO2. On the other hand, the removal efficiency of C6H6 was not significantly influenced by the temperature elevation. In the simultaneous removal of SO2 and C6H6 in the relatively low temperature range below 200 degreesC, the removal efficiency of SO2 is significantly inhibited by coexisting C6H6. When the simultaneous removal was conducted in the high temperature range, the removal efficiency of SO2 was not sensitive against the coexisting C6H6. On the other hand, the removal efficiency of C6H6 was almost independent of coexisting SO2 at all temperatures. A hypothesis of reaction mechanism was discussed based on radical reactions with SO2 and C6H6 to explain the trend observed in the experiment.