Abstract: A fluidized-bed denitrating method and a fluidized-bed denitrating device are disclosed which are capable, of effectively denitrating a combustion exhaust gas by oxidizing nitrogen monoxide occupying the major portion of NO.sub.x contained in the combustion exhaust gas to nitrogen dioxide which can be reduced at high reduction reaction rate by the oxygen contained in the combustion exhaust gas, and by reducing the nitrogen dioxide by fine carbon particles adhered to fine particles of a fluid medium. A combustion exhaust gas containing at least nitrogen monoxide and oxygen is introduced into a fluidized bed of a fluid medium consisting of fine particles with fine carbon particles adhered thereto. The fine particles of the fluid medium adsorb the nitrogen monoxide, the nitrogen monoxide is oxidized on the surfaces of the fine particles of the fluid medium to nitrogen dioxide, and the nitrogen dioxide is then decomposed into carbon dioxide and nitrogen by the reducing function of the fine carbon particles.