PURPOSE: To prevent the occurrence of harmful dust due to abrasion by a method wherein the object is gripped by a gripping device and then the object is detached from a device on which the object is fit in and at the same time with detaching or after that, a pair of gripping sections of the gripping device are so positioned that they may have the specified positional relations for adjusting the object in the specified position.

CONSTITUTION: A cassette 47 is mounted on a rest 48 which is secured on the floor 49 and is positioned between projections 48a formed on both edges of the rest 48. When both of sensors 21L, 21R detect a flange of the cassette 47, the gripping condition of the cassette 47 can be detected. Based on the result, a motor stops operation. At the same time with the motor stop or after that, a gripper 1 moves up. Then, fingers 19L, 19R are positioned vertically and therefore a center line CL1 of the gripper 1 is aligned with a center line CL47 of the cassette 47. Under such conditions, the cassette 47 moves up together with the gripper 1, going away from the rest 48. Consequently, the cassette 47 and the protrusions 48a of the rest 48 do not scrub each other, thus preventing the occurrence of harmful dust.