A position specifying device communicable with a transmitter supporting Bluetooth Low Energy, the position specifying device comprising: a signal receiving means configured, by using a plurality of antennas each having different directivity, to receive BLE radio signals transmitted from the transmitter and to measure respective receiving strengths of the BLE radio signals; and a specifying means configured to specify a position of the transmitter by comparing the respective receiving strengths measured via each of the plurality of antennas; characterised in that the BLE radio signal is in accordance with a format of an advertising packet specified in BLE standard, the advertising packet including a 128-bit field for storing a universal unique identifier (UUID); the BLE radio signal is configured to store information for identifying the transmitter in a part of the 128-bit field, and to store transmission data to be transmitted to the position specifying device in a remaining part of the 128-bit field, the transmission data being a status of the transmitter or an output value of a sensor connected to the transmitter; and the signal receiving means is configured, by receiving the BLE radio signal, to obtain the information for identifying the transmitter and the transmission data, without establishing connection between the position specifying device and the transmitter. a signal receiving means configured, by using a plurality of antennas each having different directivity, to receive BLE radio signals transmitted from the transmitter and to measure respective receiving strengths of the BLE radio signals; and a specifying means configured to specify a position of the transmitter by comparing the respective receiving strengths measured via each of the plurality of antennas; characterised in that the BLE radio signal is in accordance with a format of an advertising packet specified in BLE standard, the advertising packet including a 128-bit field for storing a universal unique identifier (UUID); the BLE radio signal is configured to store information for identifying the transmitter in a part of the 128-bit field, and to store transmission data to be transmitted to the position specifying device in a remaining part of the 128-bit field, the transmission data being a status of the transmitter or an output value of a sensor connected to the transmitter; and the signal receiving means is configured, by receiving the BLE radio signal, to obtain the information for identifying the transmitter and the transmission data, without establishing connection between the position specifying device and the transmitter. the BLE radio signal is configured to store information for identifying the transmitter in a part of the 128-bit field, and to store transmission data to be transmitted to the position specifying device in a remaining part of the 128-bit field, the transmission data being a status of the transmitter or an output value of a sensor connected to the transmitter; and the signal receiving means is configured, by receiving the BLE radio signal, to obtain the information for identifying the transmitter and the transmission data, without establishing connection between the position specifying device and the transmitter.