Reader Device and Outing Data Carrier Decision Method

In order to decide an attribute of each data carrier without manual operation, an RFID reader (30) which is carried by a user includes an identification information acquisition unit (310) reading identification information for identifying an RFID from the RFID in the vicinity in a non-contact state, a reader position acquisition unit (315) obtaining reader position information indicating a position of the RFID reader (30) when the identification information is read, an RFID position decision unit (316) deciding representative position information indicating the position of the RFID based on the obtained reader position information, and a storage unit (32) correlating the decided representative position information with the read identification information and storing them.