A switch mechanism (66) for a medical manipulator, said switch mechanism (66) comprising a moveable switching operation part (28), moving-side contacts (94, 96) provided to the switching operation part (28), and fixed-side contacts (102, 106) capable of contacting the moving-side contacts (94, 96). At least the electrical-contact sections of the moving-side contacts (94, 96) and of the fixed-side contacts (102, 106) are formed from a corrosion-resistant material.