Disclosed is an RFID-based reader configured to allow a UHF band RFID reader unit to recognize an RFID tag in a short distance, and to minimize an erroneous recognition, the reader including a gate frame discretely installed at both sides of an entrance and exit, a parabolic surface type reflective plate perpendicularly installed inside of the gate frame, an array antenna arranged on the reflective plate for receiving a tag information transmitted from an RFID tag, and an RFID reader unit for controlling an operation of the array antenna and converting the tag information received from the array antenna to a tag data.