Holding device for aligning and mounting a workpiece in an apparatus includes a receiving opening (6) provided for the holding device (20; 30), means (7) for positioning the holding device disposed in the receiving opening (6) for determination of the position of the holding device in relation to the receiving opening, wherein the holding device (20; 30) is connected with a workpiece carrier (21; 31), wherein the workpiece carrier (21; 31) is adjustable relative to the holding device, and wherein optical means (8; 11-17) are provided for viewing of the workpiece and thereby alignment of the workpiece on the holding device is performed.