To avoid interference between mutual arms, and to improve carrying efficiency by coaxially arranging two independently controlled arms on a robot arranged in a vacuum carrying chamber and used to carry a semiconductor wafer, and constituting the respective arms so as to be freely rotatable, extensible and vertically movable.

In a vacuum robot for carrying a wafer or a substrate to a process chamber from a load lock chamber in a vacuum carrying chamber 1, the robot installing opening part is arranged on the bottom side of the chamber 1 so that a robot having a lower arm 2 and an upper arm 3 independently controlled on rotation, extension and a vertical movement is installed there. An direct drive motor for the upper arm 3 containing rotors 4, 5 and stators 6, 7 are arranged in this robot, and encoders 8, 9 are installed on respwective rotor shafts. A direct drive motor for the lower arm 2 containing rotors 11, 12 and stators 13, 14 is arranged, and encoders 15, 16 are similarly installed on the respective rotor shafts.