An apparatus for surface treatment of a workpiece in a production line comprises a positioning frame (1) for the workpiece to be treated. The positioning frame has a coupling (3) for a positioning drive (4). In order to achieve an increase in the production cadence irrespective of the type of surface treatment without having to accept losses with regard to the surface quality of the coating, a hermetically sealable capsule (2) is supported against the positioning frame (1), which capsule (2) has connection lines (5) for the exchange of operating media with different operating medium supply units (6) arranged along the production line.