PROBLEM TO BE SOLVED: To provide a holder positioning support device capable of improving attachment workability and position reproducibility of a marker, and accurately performing positioning of a holder.SOLUTION: The support device 1 (holder positioning support device) includes: a holder marker 6 disposed at a holder 5； a reference marker 7 disposed at a predetermined part of a subject； a fixture 8 to which the reference marker 7 is provided and that is detachably mounted to the predetermined part of the subject； a display unit 24； and a control unit 21 for acquiring a relative position of the holder marker 6 to the reference marker 7 to display on the display unit 24.
