A quick-action clamping device for fastening a printing plate on a plate cylinder in a printing machine by a fixed clamping bar and a displaceable clamping bar which are able to be brought into a clamping position and a plate-changing position, respectively, includes a spring device for resiliently pressing the displaceable clamping bar into the clamping position with a holding force for clamping a printing plate between the displaceable clamping bar and the fixed clamping bar, and at least one re-set element for returning the displaceable clamping bar to the plate-changing position against the holding force.