A conditioning device for disinfecting, sterilizing and/or maintaining medical, especially dental, instruments comprises a distributor unit for supplying cleaning or maintenance media to the instruments, said distributor unit having respective inlets for every medium, said inlet being connected to a support for an instrument via a valve. Every valve comprises a sealing element which can be brought into a valve-opening position by means of the actuating element of the distributor unit which can be selectively positioned.
