A medical instrument including a shaft rotating device for rotating a shaft of a medical instrument about its longitudinal axis relative to a handle of the medical instrument The shaft rotating device includes a operating element arranged at a proximal portion of the shaft such that the shaft is rotatable relative to the handle against frictional forces. The shaft rotating device includes a coil spring arrangement having a surface and being in frictional contact with a surface of a counterpart for keeping the shaft and the handle rotationally stationary with respect to each other and movable against frictional forces. The operating element is operatively connected with the coil spring arrangement such that torque applied to the operating element decreases the frictional forces, while the shaft and coil spring arrangement are operatively connected such that torque applied to a distal portion of the shaft increases the frictional forces.
