A robot main body driving mechanism including wrist joint driving portion and robot main body including base detachably fixed to robot main body driving mechanism, arm including hollow shaft and wrist joint, shaft including proximal end continuous with base, wrist joint being continuous with distal end of shaft, wrist joint rotating around axis of distal end of arm, end effector attached to wrist joint, and wrist joint driving force transmission portion including hollow torque transmission tube, torque transmission tube being inserted through shaft and including distal end attached to wrist joint, wherein: by attaching base to robot main body driving mechanism, wrist joint driving portion is connected to proximal end of torque transmission tube to rotate torque transmission tube around axis of torque transmission tube and by detaching base from robot main body driving mechanism, wrist joint driving portion is separated from torque transmission tube.
