System for inserting a self-expandable occluder (12) into a patient and for releasing the occluder (12) in the left atrial appendage (10) of the patient, the system including an insertion unit (100) which has a drive unit (102) and an insertion catheter including an outer tube and an inner tube extending through the outer tube, wherein a proximal end region of the occluder is movement-coupled to the outer tube, and wherein a distal end region of the occluder, is movement-coupled to the inner tube, wherein, in order to release the occluder, the drive unit interacts with the inner tube and the outer tube such that, when actuated, the inner tube can be moved in a distal or proximal direction and the outer tube can be moved in the proximal direction or distal direction, so that the distal end and the proximal end of the occluder can be moved away from or toward one another.