A contaminant reducing device is provided. The contaminant reducing device comprises: an exhaust gas tube for supplying exhaust gas from a combustion engine a cleaning water supply tube for supplying cleaning water a scrubber for spraying cleaning water, which is supplied through the cleaning water supply tube, to exhaust gas supplied through the exhaust gas tube an oxidation unit connected to the exhaust gas tube so as to oxidize the exhaust gas by discharging electricity, emitting ultraviolent rays, or spraying an oxidizer and a cleaning water discharge tube for discharging cleaning water from inside the scrubber.
