A RFID tag capable of storing and restoring flag data is described. The RFID tag includes an analog block for generating a driving power using a radio frequency signal received through an antenna. The driving power is used to store the flag data. A digital block is operated using the generated driving power and processes RF data that is transmitted and received via the analog block in order to store the flag data in the analog block. A memory block reads and writes data to a nonvolatile ferroelectric capacitor depending on a control signal from the digital block. The analog block supplies the flag data to the digital block during an activation time period of a power-on reset signal.