For vacuum treatment of workpieces by a multitude of distinct processing stations (P.sub.11-P.sub.1n, P.sub.21-P.sub.2m) the processing stations are grouped in two groups (I and II). The workpieces are handled towards and from the processing stations of the first group (I) simultaneously, whereat the workpieces are treated by the processing stations of the second group (II) in a selectable individual sequence.