An articulation device for a medical instrument includes a coupling for releasable mechanical connection of the articulation device to a tool or to the distal end of a shaft, a locking device on the coupling for locking the mechanical connection, and an articulation, which enables the coupling to be angled relative to an end of the articulation device remote from the coupling. The locking device is designed such that the mechanical connection is locked in a predetermined working angular position of the articulation and is releasable in a predetermined release angular position of the articulation.
