The crystallized CeO2 films were grown on Si(100) wafer by RF magnetron sputtering. For measurements of those films, CeO2 films were analyzed with XRD, SEM, AES, RBS, and TEM. CeO2 films by sputtering were crystallized with (111) plane without increasing substrate temperature and annealed films' orientation was riot changed. For interaction between CeO2 and Si substrate, no secondary phase was observed while SiO2 layers were generated between CeO2 and Si substrate when CeO2 films deposited with each condition were annealed in the air and N-2 atmosphere. For this reason, it was assumed that Si substrate was oxidized by excess oxygen in CeO2 films during annealing. (C) 2004 Elsevier B.V. All rights reserved.