The invention relates to a medical apparatus having a medical optical appliance and a holding device with at least two holding arms which are connected movably to one another with at least one degree of freedom of movement via a joint and with an actuator which is connected to the two holding arms in such a way that a force can be exerted via the actuator between the two holding arms in the direction of the degree of freedom of movement. A control unit comprises a first regulator for outputting a first control signal to the actuator via an adjusting element. The medical optical appliance is mounted on the holding device.