A medical instrument includes instrument parts which can be releasably connected to one another. One part includes a hollow-cone-shaped receiving space and another part includes a cone-shaped coupling section which can be inserted into the receiving space to connect the parts. The coupling section includes a locking receiver for a locking element of the receiving space and which can be brought into and out of engagement with the locking receiver. A securing element moves between a position holding the locking element in a locking position, and a position releasing the locking element. An actuation element projects into the receiving space of the first instrument part, engages into the locking receiver in the locking position of the locking element and is movable in the direction of its middle axis. The middle axis of the actuation element is aligned in the proximal direction obliquely to a middle axis of the receiving space.
