A reading device configured to read inherent information of one or more commodities from an RFID tag attached to each commodity, the reading device comprising: a placing region for receiving the commodities; two or more antennas (24, 25), arranged at different vertical locations with respect to the placing region, the two or more antennas (24,25) configured to transmit radio waves from the different vertical locations and receive a response with the inherent information from each RFID tag, wherein the at least two antennas (24, 25) include a first antenna arranged at a lower side of the placing region, the first antenna transmitting radio waves from the lower side of the placing region, and a second antenna arranged at a wall extending vertically along the placing region, the second antenna transmitting radio waves from the wall toward the placing region; a specifying unit configured to identify one or more commodities in the placing region based on the inherent information read through the antennas (24, 25); a selection unit configured to select one specific commodity to be moved from the placing region among other commodities placed in the placing region based on the radio waves received from the at least two antennas (24, 25) and the identification by the specifying unit; and a guide unit configured to provide guide information for instructing a movement of the one specific commodity selected by the selection unit from the placing region, wherein the selection unit is further configured to deduce an overlapping relationship of the one or more commodities when other commodities overlaps onto the RFID tag of the commodity, to determine the overlapping relationship based on a received signal strength of the inherent information and to select the one specific commodity from the commodity at the higher position in a descending order. a placing region for receiving the commodities; two or more antennas (24, 25), arranged at different vertical locations with respect to the placing region, the two or more antennas (24,25) configured to transmit radio waves from the different vertical locations and receive a response with the inherent information from each RFID tag, wherein the at least two antennas (24, 25) include a first antenna arranged at a lower side of the placing region, the first antenna transmitting radio waves from the lower side of the placing region, and a second antenna arranged at a wall extending vertically along the placing region, the second antenna transmitting radio waves from the wall toward the placing region; a specifying unit configured to identify one or more commodities in the placing region based on the inherent information read through the antennas (24, 25); a selection unit configured to select one specific commodity to be moved from the placing region among other commodities placed in the placing region based on the radio waves received from the at least two antennas (24, 25) and the identification by the specifying unit; and a guide unit configured to provide guide information for instructing a movement of the one specific commodity selected by the selection unit from the placing region, wherein the selection unit is further configured to deduce an overlapping relationship of the one or more commodities when other commodities overlaps onto the RFID tag of the commodity, to determine the overlapping relationship based on a received signal strength of the inherent information and to select the one specific commodity from the commodity at the higher position in a descending order.