A manipulator joint displacement detection mechanism includes a manipulator which has a actuating unit and a joint. A first transmission member is connected to the joint, and provided movably to displace the joint. A second transmission member moves corresponding to movement of the first transmission member. A guide guides movement of the second transmission member. A guide fixing part fixes one end and the other end of the guide. A sensor detects a moving distance of the second transmission member in the proximal end portion of the manipulator.
