An information processing apparatus having a security server and a reader/writer includes a demodulator of the reader/writer for reading information from an RFID tag, a modulator of the reader/writer for writing information into the RFID tag and also writing area information indicating whether the RFID tag exists in a secret area, a memory for storing the information read from the RFID tag by the demodulator and the information written into the RFID tag by the modulator, and a controller for controlling the demodulator and the modulator. When the area information read from the RFID tag by the demodulator indicates that the RFID tag exists in a predetermined area, the controller precludes from reading predetermined information stored in the RFID tag, and controls the modulator so as to write the area information indicating that the RFID tag does not exist in the predetermined area.