An instrument holder is described for mounting a medical instrument on a joint arm, comprising a body, a holder for holding the medical instrument on the body, and a coupling element for attaching the body to the joint arm. The holder comprises a threaded shank provided with an external thread, a receiving disc and a locking element provided with an internal thread. The receiving disc has a through-hole, by which the receiving disc can be put on the threaded shank and is rotatable about the threaded shank.
