A device for treating a disc-shaped substrate is disclosed, comprising a support which has a support face for the disc-shaped substrate and a support adapter which can be coupled to the support and can support a mask used for treating the disc-shaped substrate, wherein an interface is provided which detects the coupling of the support adapter to the support and wherein a control system is provided which cooperates with the interface and detects whether the support adapter is coupled to the support, in particular whether the interface is occupied. A support adapter for use in a device of this type is further disclosed.