A medical instrument having a shaft, at the proximal end of which a handle is arranged, wherein the shaft is rotatable about its longitudinal axis and can be secured in various positions of rotation relative to the handle via a licking mechanism. In order for a medical instrument with a shaft rotatable about its longitudinal axis to be designed in such a way that, while being easy to handle, it permits a large number of secure and positionally precise rotations of the shaft with respect to the handle, the licking mechanism is designed as a latching mechanism which has a perforated disk with recesses and latching elements, wherein the latching elements and/or the perforated disk are spring-loaded relative to each other, and at least one of the latching elements engages in a corresponding recess of the perforated disk in order to fix the shaft.