A manipulator includes a hollow joint shaft, wires extending through the joint shaft, pulleys mounted on an end of the joint shaft, for imparting a drive force to the wires, a distal-end working unit mounted on another end of the joint shaft, for being actuated by the wires, and a sealing member for preventing liquid such as blood from flowing from the distal-end working unit through the joint shaft to a connector. The sealing member has holes defined therein, and the wires are slidably inserted through the holes.