the holders 41 is filled with new semiconductor wafers and the holders on which the already coated semiconductor wafers and the spacing members are removed from the storage space 47 during the loading and unloading of the storage spaces 46 47 the gas atmosphere inside the pre chamber 10 the reaction chamber 4 and the terminal chamber 11 remain unaffected by the surrounding atmosphere above all however there is no need for the heating device 5 to be cooled down to ambient temperature and then being re heated thereafter for the heating device 5 it is possible depending on the epitaxial process to be carried out to use either a resistance heated oven a source of heat radiation an induction heater or any other source of heat insofar as the system shown in fig2 and 3 is in agreement with the system described hereinbefore identical individual elements thereof are indicated by the same reference numerals thus the function of these identical elements is not reexplained within its region of epitaxial growth 2 lying between the pre chamber 10 and the terminal chamber 11 it comprises two chambers 70 and 71 disposed transversely in relation to the direction of transfer of the holders 41 supporting the semiconductor wafers 40 and the spacing members 43 each of these reaction chambers is provided with an inlet tube 73 74 through which the respective reaction gas in supplied as well as with a deaerating or exhaust tube 75 76 in order to avoid or to reduce a gas exchange between the reaction.