Provided is a Radio Frequency Identification (RFID) reader that can minimize collision among RFID readers in an environment where there are a plurality of RFID readers within a limited operating environment by making each RFID reader select a channel at different delay time based on a random value, and a method for controlling operation of the RFID reader. The RFID reader includes a random value generating unit; a reader control unit for adaptively deciding a counter value for generating the random value; an anti-collision unit for preventing collision among a plurality of tags; a reader transmitting unit for generating a reader command message determined by the anti-collision unit, encoding the reader command message, and modulating the reader command message; a reader receiving unit for demodulating and decoding a tag signal; and a channel operation control unit for selecting a channel to be used for the communication with the tag.