Ba-2(Fe1-xInx)(2)O-5 was prepared by a solid-state reaction under a N-2 flow. It was revealed that the solid solutions had a cubic perovskite structure with disordered oxygen vacancies at room temperature. Thermogravimetry and X-ray diffraction measurements revealed that Ba-2(Fe1-xInx)(2)O-5 can reversibly react with CO2. It was found that the equilibrium temperature of the reaction could be controlled by preparing solid solution.