Ceria (CeO2, Cerium Oxide) with excellent surface exchange coefficient is widely used as a material to improve the performance of solid oxide fuel cell (SOFC) at low temperature due to its high ion conductivity and surface exchange coefficient. In this study, CeO2 process by atomic layer deposition (ALD) using (i-PrCp)3Ce and water as Ce precursor and oxidant, respectively, was studied and optimized. As a result, CeO2 process with a growth rate of 3Å/cycle at 200℃ was successfully developed. We further conducted studies to improve the performance and durability of the cathode of low temperature SOFC with ALD CeO2 overlayer. The SOFC with the overlayer of ALD CeO2 5cycle showed 45% higher and 6.5 times higher performances after 0hr and 10hrs of operation at 450℃, respectively, than the one without overlayer.