Catalytic chemical vapor deposition(Cat-CVD) is a method of depositing thin films using radicals formed by the catalytic clacking of gas molecules on a heated catalyzer. Despite its simple configuration, the Cat-CVD can form highly-dense films with a high deposition rate, and realize excellent interface quality between a deposited film and a substrate due to its plasma-damage-less feature. The usage of appropriate source gas and a catalyzer material enables us to form Al₂O₃, GaN, and organic films such as poly-tetra-fluoro-ethylene(PTFE) as well as Si-related films. The problem of catalyzer aging, which becomes an obstacle for efficient mass-production, could be solved by the careful selection of catalyzer temperature and/or the removal of a surface degraded layer by post-annealing. The Cat-CVD technology has a wide field of application such as electronic devices, encapsulation films against moisture or oxygen, water-repellent coatings, and the removal of carbon-containing layers using highly-dense hydrogen radicals.