Organic catalytic CVD (O-Cat-CVD) is an extension of the conventional Cat-CVD technique to organic substances. O-Cat-CVD utilizes metal organic (MO) compounds as CVD sources and provides various types of organic-inorganic hybrid materials at low substrate temperature below 200^oC. The growth instrument using high-melting-temperature metal filaments seems to be simple and easily scaled up. Chemical reactions at the hot filament, vapor phase reactions and substrate surface reaction must be taken into account. Although deep understanding is necessary to the mechanism of O-Cat-CVD growth, the method is quite promising as a key thin-film growth method in the industry like film-based electronics which provides various types of flexible devices such as flexible OLED and flexible solar cells using plastic film substrates.