A device for distraction of a bone segment from local bone, or endo-distractor. The device has a rotatable, smooth shaft adjoined by a straight anchoring screw. During the unscrewing of the anchoring screw a carrier piece transfers the axial movement but not the rotation to the bone segment. The carrier piece for the bone segment is a pressure plate which is formed with an open slit and which, by being pushed orthogonally, with respect to the longitudinal direction of the shaft, onto the shaft, can be secured on the latter in the axial direction.
