PURPOSE: To remove a dead zone produced at the center of a frame face by disposing a frame antenna on the circumference of a conveyor for question, and equipping its upper side with an individual read antenna having a hinge system hanging tool for receiving.

CONSTITUTION: A frame antenna 2 is disposed on the circumference of a conveyor 1, an individual receiving antenna 3 hung at the top side thereof in a hinge system is provided so as to remove the antenna 2 at the time when an object approaches, and is used. The antenna 3 is arranged slightly upward of substantially the center of a frame face. In order to prevent fatigue of a connection wire, the antenna 3 is connected to the receiver of a transmitting and receiving unit by inductive coupling of two coils. Thereby a dead zone produced at the center is removed, and irradiation and reading can be achieved very precisely.