A fluidized bed reactor for hydrogen chloride removal by calcium absorbent was developed as a means to reduce hydrogen chloride concentration to less than 10ppm in the gasification gas of the MCFC power generation system. The optimum calcium absorbents were evaluated from the chemical equilibrium and kinetics in the presence of CO2. It was found that the selective reaction between slaked lime and hydrogen chloride took place without competitive inhibition by CO2 at the temperature of 573 K. An absorption experiment with slaked lime in a fluidized bed reactor revealed that hydrogen chloride concentration could be reduced to less than 10 ppm until the conversion ratio of calcium reached 0.65.