PROBLEM TO BE SOLVED: To provide a retractor fixing mechanism and retractor fixing device capable of easily and meticulously adjusting a fixing position of a retractor and facilitating intended incision by the retractor.SOLUTION: A retractor fixing mechanism 50 includes a slider 51, a fixing part 52, and a swing shaft 53. The slider 51 is slidably supported by an arm part 31. The fixing part 52 is formed into a shape extending in a longitudinal direction D3, and fixes the retractor 80, with it inserted into a positioning hole 82 formed in the retractor 80. The swing shaft 53 connects the slider 51 and the fixing part 52 so as to swing relative to each other.