Abstract: Disclosed is a robot having multi-joint arms movable in a horizontal plane, which is mechanically compact as well as small sized and operated with high precision and a minimum output of drive sources, substantially comprising a robot body (1), a cylindrical mount (2) movable vertically of the robot body through a guide means (3) and a slider means (4), a vertical threaded shaft (6) rotatably journaled in the robot body and operatively connected to the cylindrical mount, the vertical threaded shaft being rotated by a first drive motor (5) to vertically move the cylindrical mount therealong, a first arm (9) having one end operatively connected to the cylindrical mount so as to be turningly moved in a horizontal plane by a second drive motor (12), a second arm (10) having one end operatively connected to the opposite end of the first arm so as to be turningly moved in a horizontal plane by a third drive motor (17), and a control R shaft (11) rotatably mounted on a free end of the second arm so as to be rotated b