A bench-scale test (800 Nm3/h) for electron beam treatment of flue gas was conducted. It was concluded that the method is favourable for treatment of flue gas with a high SO2 concentration (5,500 ppm) at low electron beam irradiation (5 kGy). Results are consistent with the claim that SOx is removed from flue gas by the reaction of SOx with ammonia, and the intermediate salts formed are oxidised by radicals to sulphate salts consisting mainly of ammonium sulphate (a N-fertiliser). A typical flue gas desulphurization (FGD) method such as the wet limestone process cannot remove NOx and SO3 effectively (Ando, 1990), but the electron beam process removes SO2, SO3 and NOx simultaneously without generating waste water and CO2.