A medical manipulator includes a treatment part; a joint part that is provided at an end of the treatment part and configured to be operated through turning of a rotating body; an elongated member that has a longitudinal axis and is connected to the end of the joint part opposite to a side where the end effector is provided; a driving part that is provided on a proximal side of the elongated member and is configured to supply a driving force for operating the second coupling member or the like; a driving wire member that is connected at least to the second coupling member of the joint part and is stretched between the second coupling member and the elongated member; and a wire relaxation mechanism that is configured to relax the driving wire by changing the path length of the driving wire.