The catalytic reaction between carbon monoxide in the anthracite flue gas and air was investigated on the various catalysts such as manganess dioxide, cupric oxide and their admixtures. Complete removal of carbon monoxide occurred both on $MnO_2$ and 30\% $MnO_2$-70\% CuO at 250$^\circ$C, on CuO at 450$^\circ$C, on 50\% $MnO_2$-50\% CuO at 200$^\circ$C, and on 70\% $MnO_2$-30\% CuO at 180$^\circ$C. Carbon monoxide removal efficiency was decreased linearly with increasing inlet carbon monoxide concentration over the range of transitional temperature, but was not affected above the effective reaction temperature. Residence time of gases in the reactor, over the range of 0.9 to 1.8 seconds, gave no effect on carbon monoxide conversion.