Abstract: The invention relates to a device for treating micro-circuit wafers, comprising a feed station for cassettes with wafers, at least one treatment station in which wafer carriers and treatment means co-acting therewith are disposed and a transfer station provided with transferring means for removing wafers from the cassettes and placing them in the wafer carriers and, after treatment, removing the wafers from the wafer carriers and re-placing them in the cassettes. At least the feed station and the treatment station are embodied as separate connectable units having in cross section an at least partially regular polygonal periphery, wherein these units connect onto other units at the position of the sides of the regular polygonal periphery.