Wireless tags that store identification information are widely used. Wireless tags are attached to products such as merchandise or equipment and also to buildings and around roads. In the wireless tag, a radio frequency identifier (RFID) tag is included that stores ID information or the like and that performs a wireless communication within a near distance of several centimeters to several meters. When a communication device (reader and writer) reads the RFID tag, merchandise information or positional information can be acquired from information associated with the read tag ID.