To provide a bed driver that can easily detach a bed from it without taking off any of members composing the bed, and that can prepare the medical treatment simply by placing a bed for patient on it and further, can accurately position the bed which eliminating chattering in the direction of moving the bed.

In this bed driver, a sucking port 4 for performing vacuum exhaustion is disposed near the inside of a special belt 2 provided with tiny holes all over the belt. A bed 8 is placed on the special belt 2 and then, sucked by the sucking port 4. With the motion of the special belt 2, the bed 8 moves. Moreover, a roller unit 10 is provided to prevent horizontal deviation when the bed 8 moves longitudinally.