A device and method for treating all types of parts, in particular bones, organs, etc. of the human/animal body, which includes a housing (3), a tool (1) associated with the housing (3), and an actuation unit causing a relative movement between the housing and the tool. The device is designed and constructed to permit process control by the user, while utilizing the specific possibilities of robotics and computer-assisted navigation in such a manner that the position of the tool can be detected, and that the position of the body part being treated can be detected or predetermined, with the actuation unit being activatable in such a manner that it moves the tool within a predetermined work area to a predetermined relative position with respect to the body part being treated.