Provided is an apparatus for controlling supply of power to a radio frequency identification (RFID) tag, in which an internal large-capacity memory of an RFID tag is physically divided into a plurality of memory blocks, and power is selectively supplied to each of the divided plurality of memory blocks depending on the case, thereby reducing power consumption of the RFID tag. The apparatus includes a first memory configured to store information which is used to perform an inventory operation with an RFID reader, a second memory configured to store a file and data associated with the RFID tag, and a control unit configured to perform the inventory operation with the RFID reader by using the inventory information stored in the first memory, and when a command for accessing the second memory is received from the RFID reader, allow power to be supplied to the second memory.