A medical manipulator system (1) includes a guide instrument having a treatment tool channel, an insertion body (31) inserted into the treatment tool channel, a power source unit (56) attachable to and detachable from the insertion body (31), a guide rail (53) having a first region which corresponds to a state in which the joint part of the insertion body (31) is located in the treatment tool channel and a second region which corresponds to a state in which the joint part is exposed from the distal end of the treatment tool channel, and the guide rail is configured to guide the power source unit (56) to advance and retract in a predetermined linear direction including the first region and the second region, and a regulating part (70) interposed in a boundary between the first region and the second region in an advancing/retracting path of the power source unit (56) in the guide rail (53) and the regulating part is configured to regulate a movement of the insertion body (31) from the second region toward the first region in a state in which the insertion body (31) is attached to the power source unit (56).
