Abstract: A work carrier capable of moving a work stage 45 to an arbitrary position in the left/right direction and stopping the work stage 45 thereat with an accuracy equivalent to that of a conventional carrier or above through an inexpensive structure. The work carrier comprises a fixed guide rail member 15 and movable guide rail members 17, 18, 19 mounted on a supporting table 10, a driver 16 for moving the movable guide rail members to the left and the right, rail member interlocking mechanisms 35a, 35b for interlockingly operating the movable guide rail members 17, 18, 19, and the work stage 45 mounted on the movable guide rail member 19, wherein the driver 16 is a motor having a rotational speed being varied by inverter control and employing an open loop rotation control system, and a plurality of stopper members 52a, 52b, 52c are provided in order to stop the movable guide rail member 17 at a specified position.