A medical or dental handpiece comprising a tool holding/releasing device with a hollow shaft that can be put into a drive motion for holding a treatment tool, wherein the hollow shaft extends along a central axis and has a tool receptacle opening, a first holding unit and a second holding unit separate from the first holding unit and axially offset from the first holding unit relative to the central axis, wherein both holding units are designed to axially secure a treatment tool held in the hollow shaft and to transmit a torque to the treatment tool, and wherein both holding units have at least one shaped element each and a bore penetrating the outer wall of the hollow shaft, in which the at least one shaped element can be held in such a way that it projects through the bore into the interior of the hollow shaft, a locking sleeve operatively connected to the shaped elements that can move relative to the hollow shaft and that surrounds the hollow shaft and an operating element operatively connected to the locking sleeve for the movement or sliding of the locking sleeve.
