Abstract: A surface deposition or surface treatment reactor, in particular for chemical vapor deposition, has an annular reaction chamber (C.sub.R) delimited by two tubular walls (1, 2), in particular of quartz. A first hearing unit is arranged inside the tubular wall (1) and a second heating unit is arranged around the outer tubular wall (2). Said units are controlled by heat-regulating means in order to ensure a predetermined longitudinal temperature profile in the reaction chamber (C.sub.R). The gas phase is distributed at a longitudinal end of the chamber (C.sub.R) through distribution ducts (18) and removed by suction at the other end through pumping ducts (20). The substrates (S), which may be very numerous, are swept simultaneously by the gas phase and the perfect control of the temperature distribution and of the flow makes it possible to obtain a uniform treatment of the desired type which is identical for all the substrates.