Abstract: The subject matter of the present invention relates to a clamping device for clamping a tool or a tool holder (2) in a machine spindle (1), comprising a drawbar (6) that can axially move back and forth between a clamping position and a release position, a clamping spring (18) for actuating the drawbar (6) in the direction of the clamping position, a minimum of one sensor (20) for monitoring the clamping force, and a clamping cone (8) having a plurality of clamping elements (13 [sic; 9]) that rest against its outside surface, which clamping elements, via the axial movement of the clamping cone (8) by means of the drawbar (6), can be moved back and forth between a clamping position in which the tool or tool holder (2) is retained and a release position in which the tool or tool holder (2) is released.