A medical manipulator has a distal-end working unit including an end effector. The distal-end working unit has a rotor having a hollow tube rotatable in unison with the end effector and a rotational support tube having a posture variable with respect to the shaft. The rotor is rotatably supported by an inner circumferential surface of the rotational support tube. Engaging members that are disposed in side holes formed in the rotational support tube have inner ends inserted in an annular groove.