A holding device for medical purposes having a carrier arm on whose distal end a medical instrument can be secured and having at least one joint for positioning the carrier arm and/or the medical instrument, where the joint can be converted between the position that releases the joint and the position that blocks the joint. The holding device provides simple operation, reliable positionability, and can be cleaned well. The joint comprises at least two joint members that enter into active connection with one another by mutually engaging catching elements, where the catching elements are positioned essentially perpendicular to the longitudinal direction of the carrier arm and are pre-tensed with respect to one another by a spring element, and that in the joint at least one hydraulically or pneumatically spreadable expansion element is positioned by which the joint can be converted into the position that releases the joint.
