NOVELTY - Processing of flue gas involves generating flue gas through plasma-generating electrode, reacting plasma with flue gas, generating flue gas containing hydrogen, oxygen, hydroxide and ozone as active particles, reacting flue gas with sulfur dioxide and nitrogen oxide, obtaining flue gas containing nitrate ion and divalent sulfate ion, reacting the obtained flue gas in presence of ammonia gas, obtaining flue gas-containing charged-ammonium salt particles, applying direct current bias electric field, removing charged-ammonium salt particles and purifying the resultant flue gas.    USE - Processing of flue gas discharged in thermal power plant and industrial boiler.    ADVANTAGE - The method efficiently and economically enables the processing of flue gas, with reduced energy consumption, by a simple process.    DETAILED DESCRIPTION - Processing of flue gas involves generating flue gas through plasma-generating electrode, such that flue gas includes electrons, positive ions, electrically-neutral particles and surface-charged dust particles, applying direct current bias electric field, removing dust particles by adsorption, reacting plasma with flue gas containing oxygen and water molecules, generating flue gas containing hydrogen, oxygen, hydroxide and ozone as active particles, reacting the flue gas with sulfur dioxide and nitrogen oxide, obtaining flue gas containing nitrate ion and divalent sulfate ion, reacting the obtained flue gas in presence of ammonia gas, obtaining flue gas-containing charged-ammonium salt particles, applying direct current bias electric field, removing charged-ammonium salt particles by adsorption, purifying the resultant flue gas and discharging. The plasma-generating electrode structure comprises several high-voltage electrodes, ground electrodes and cylindrical conductors. The high-voltage electrodes, ground electrodes and cylindrical conductors are wrapped with insulating medium. The high-voltage electrode and ground electrode are intersected with each other to form mesh structure. An INDEPENDENT CLAIM is included for apparatus for processing of flue gas.