A reading device includes an antenna, a data storage unit, and a controller. The antenna is configured to receive tag information from RFID tags attached to objects in a receiving range. The data storage unit stores an object ID in association with a predetermined total number of RFID tags on an object corresponding to the object ID. The controller is configured to start a reading operation in which the antenna emits radio waves and receives tag information from the RFID tags. The controller counts the number of RFID tags associated with the object ID according to the tag information received during the reading operation. The counted number is compared to the predetermined total number associated with the object ID, and the controller controls a timing for terminating the reading operation based on the comparison.