We investigated the use of Ba2TiO4 to remove CO2 from a flow gas at high temperatures. Experiments using a CO2/N, gas and a vertical reaction tube showed that the CO2 concentration of the exit gas can be reduced to 1% or less at 500 to 800 degrees C (and to even 0.1 % or less at 600 degrees C) when the space velocity (SV) of the flow is 2000 h(-1). Also. the CO2 concentration changes for the gas mass flow at 700 degrees C or lower. From the results of reaction rate analysis of Ba2TiO4 and Co-2, at temperatures of 550 degrees C and higher, the activation energy was 12.5 kJ/mol. indicating that this range is a diffusion-rate controlled area. The reaction rate had a linear correlation with the CO, concentration from 500 to 800 degrees C, and the estimated reaction degree was 0.96. These results indicate that Ba2TiO4 can effectively remove CO2 from exhaust gas at high temperatures.