The invention relates to an apparatus for mounting components on a substrate. The apparatus comprises a bond head with a component gripper, a first drive system for moving a carrier over relatively long distances, a second drive system which is attached to the carrier for moving the bond head back and forth between a nominal working position and a stand-by position, a drive attached to the bond head for rotating the component gripper or a rotary drive for rotating the substrate about an axis, at least one substrate camera attached to the carrier and at least one component camera. At least one reference mark is attached to the bond head or the component gripper.