A multi-joint manipulator enabling an easy teaching method and an increase in the operating speed of arms, and capable of mounting a heavy object in a small space. The multi-joint manipulator comprises a plurality of arm bodies installed in series, joint parts rotatably connecting the adjacent two arm bodies to each other, joint parts with the rotating shafts of adjacent joints tilted by 90 DEG , at least one line body disposed at the joint parts coaxially with the rotating shafts, and joint parts formed of servo-motors and reduction gear mechanisms. The servo-motors and the reduction gear mechanisms are positioned coaxially with the rotating shafts of the joints.