Patent attributes
A wafer mapping device that recognizes the existence of wafers along with the descending and opening of a front door (2a) of a closed type clean container (2) in a state where the front door of the closed type clean container for mounting and housing wafers (4) on any one of or a plurality of shelves among a plurality of internal shelves is made tightly contact to a port door (13) of a load port (12), comprising a swinging member (22) coupled to the port door so as to swing around predetermined horizontal axes parallel to the port door, a pair of sensor portions (20) fixed to the swinging member and mutually separated as well as protruding towards the clean container from the swinging member above the port door, a light emitting device (20a) and light receiving device (20b) fixed one each to the pair of sensor portions and facing each other, and swinging drive means (25) for rotating the swinging member around the horizontal axis to an angle where the wafers enter between the light emitting device and the light receiving device without the light emitting device and the light receiving device contacting the wafers, and inserting the pair of sensor portions into the interior of the clean container.