A manipulator (10) includes a hollow joint shaft (48), wires (54a, 54b and 54c) extending through the joint shaft (48), pulleys (50a, 50b and 50c) mounted ON an end of the joint shaft (48), for imparting a drive force to the wires (54a, 54b and 54c), a distal-end working unit (12) mounted ON another end of the joint shaft (48), for being actuated by the wires (54a, 54b and 54c), and a sealing member (64) for preventing liquid such as blood from flowing from the distal-end working unit (12) through the joint shaft (48) to a connector (15). The sealing member (64) has holes (66a, 67a, 66b, 67b, 66c and 67c) defined therein and the wires (54a, 54b and 54c) are slidably inserted through the holes (66a, 67a, 66b, 67b, 66c and 67c).
