Abstract: A device for carrying a thin plate-like substrate such as a semiconductor wafer and controlling its position by floating it with an inert gas of low impurity concentration. A transferring unit and a controlling unit are respectively provided with gas nozzles for floating a thin plate-like substrate and with a gas exhausting and circulating system, and a plurality of them are in combination with each other in a sealing state. The controlling unit, further, has a vacuum suction hole at its controlling center, and is provided with nozzles for controlling the thin plate-like substrate in its radial and circumferential direction respectively and with nozzles for stopping the thin plate-like substrate or sending out it to the next unit too.