PURPOSE: To visually recognize a code of a wafer contained in a wafer cassette without direct contact with the wafer by so moving many wafers contained in many stages in a first cassette to a second wafer cassette as to be sequentially deviated in superpositions of the wafers.

CONSTITUTION: Since an end face 16a of a first contact moving member 16 is obliquely formed, wafers 1 moved to a second wafer cassette 14 are sequentially deviated in superpositions. Thus, codes adhered to the respective wafers 1 are simultaneously visually recognized from above. Then, a moving plate 13 is moved toward a second contact moving member 17, its end face 17a is brought into contact with the wafer 1 in the cassette 14, the end 17b of the member 17 is introduced into the cassette 14 as it is, and the wafer 1 is again returned to a first cassette 3. Thus, a desired wafer can easily be removed.