PURPOSE: To sort products by reading an with a sensor and identification mark provided on a receiving plate on which different types of products are placed.

CONSTITUTION: A receiving plate A1 on which a product B1 is placed and a receiving plate A2 on which a product B2 is placed are fed in a mixed condition on a conveyer. The rear end of the right side surface of the receiving plate A2 is formed with a mark consisting of a recessed part. When a receiving plate A1 is transported and its end is detected by light receiving elements 28, 30, the conveyer 26 stops. At the side of a stopping position, an identification device 31 which identifies the types of the receiving plates A1, A2 is provided. When the identification device 31 receives a receiving plate detecting signal, a piston rod 36 extends, so that a press plate 38 goes forward, and a patch 46 is pressed against the center of the side surface of the receiving plate A1. An identification instrument 32 consisting of an optical distance sensor is installed on the mounting plate 44 of the patch 46, and either of the receiving plates A1, A2 is discriminated by whether the reflection surface of reflected light coincides with the sides of the receiving plates A1, A2. It is thus possible to sort products with a sorting device by this discrimination.