PURPOSE: To permit easy manufacture and assembly of a large-sized thin film forming machine by forming each of the plural chambers of a titled device provided with plural chambers such as vapor deposition chambers or the like into a treating chamber unit and uniting these chamber units to the thin film forming device.

CONSTITUTION: A base body feed chamber A contg. a roller 3 on which a base body 2 to be formed thereon with a thin film has a conveying roller R and plays the role of the chamber A when the roller 3 is rotated toward an arrow and conversely as a base body take-up chamber E when the roller is rotated reverse. A vapor deposition chamber to form the thin film is disposed with the roller R, a plate 9 for preventing deposition, a heater 34, etc. and serves as a chamber B or C, D simply by changing the conveying path for the body 2. These chambers are connected to each other by means of the holes 10, of flanges F, bolts BT and nuts N to one body or separated from each other. A partition plate 8 segmenting each chamber is provided in 1W2 sheets integrally with each chamber. Evaporating sources 25W27 and dischargers 37 are provided in the chambers BW D.