PROBLEM TO BE SOLVED: To provide an apparatus efficiently treating exhaust gas and stably supplying COover a long time.SOLUTION: The combustion exhaust gas treating unit is provided with at least a flow passage of gas to be treated, a first electrode, a second electrode and a dielectric disposed in the flow passage, and is provided with a plasma generation portion generating plasma by applying voltage between the first electrode and second electrode and generating discharge, and a catalyst portion including a catalyst promoting the reaction of the gas to be treated, disposed at a position where the plasma generated by the plasma generation portion in the flow passage is present and including gold particles fixed onto an inorganic material.
