The device comprises a carrier for a workpiece which carrier can by means
of drive means be moved along a vertical and a horizontal axis and has an
approximately planar contact surface for the workpiece, whereby the
workpiece can be held on the contact surface by means of contact means of
the carrier, especially vacuum, a retaining ring on the carrier
encircling the contact surface and projecting downwards beyond the
contact surface and having an inner diameter which is slightly larger
than the outer diameter of the workpiece. At least three centering cams
are arranged on a circle, the centering cams can be moved synchronously
and in a radial direction by means of a centering drive, the centering
cams having a supporting surface oriented on the top. The supporting
surface has an approximately vertical stop surface as well as a stop
being radially outwards of the stop surface adapted to engage the outer
side of the retaining ring, when the centering cams are radially moved
towards each other and the carrier is set down until coming close to our
onto the centering cams. A robot is provided so that a workpiece can be
loaded on cams or removed from it, the outer diameter of the retaining
ring and the position of the stop surface and of the stop being
dimensioned such that the workpiece is arranged approximately in a
centered way relative to the vertical axis of the carrier when the stops
of the centering cams engage the retaining ring.