Abstract: Command control is performed by the same command control unit even in the communication in which either an RF analog section or a contact communication terminal section is used, and thereby, both of RF communication and contact-type serial communication can be performed by using a predetermined communication protocol stored in a storage unit in common, and both of the RF communication and the contact-type serial communication can be performed by using the single communication protocol, resulting that a circuit configuration of a data carrier capable of performing the RF communication and the contact-type serial communication can be simplified, and memory capacity necessary for storing the communication protocol can be reduced.