Gas supply arrangement, especially for a CVD process reactor for growing an epitaxial layer

is described, inter alia, a gas supply arrangement (10) for a process reactor (270). Gas supply assembly (10) includes at least one switching unit (420), a process gas line (470) and an auxiliary line (460). The process reactor (270) contains at least one gas inlet port (404). A reactor conduit (450) lies between the switching unit (420) and the gas inlet port (404). The reactor line (450) is shorter than one meter, thereby creating excellent operating characteristics of the gas supply arrangement (10).