A distance measuring device comprising: a transmission circuit configured to transmit a signal for distance measurement to another distance measuring device; a reception circuit configured to receive the signal for distance measurement transmitted form the other distance measuring device; a filter configured to restrict the signal for distance measurement transmitted from the transmission circuit and a signal for distance measurement received by an antenna within a desired frequency band; and a first switching circuit configured to switch a route between the transmission circuit and the antenna and a route between the reception circuit and the antenna, characterized in further comprising: an impedance circuit configured to have a higher impedance than an impedance of the antenna; a second switching circuit; a third switching circuit; and a fourth switching circuit, wherein the second switching circuit is configured to switch conduction and non-conduction between the fourth switching circuit and the transmission circuit, the third switching circuit is configured to switch conduction and non-conduction between the fourth switching circuit and the reception circuit, and the fourth switching circuit is configured to switch conduction and non-conduction between the impedance circuit and both of the second switching circuit and the third switching circuit. a transmission circuit configured to transmit a signal for distance measurement to another distance measuring device; a reception circuit configured to receive the signal for distance measurement transmitted form the other distance measuring device; a filter configured to restrict the signal for distance measurement transmitted from the transmission circuit and a signal for distance measurement received by an antenna within a desired frequency band; and a first switching circuit configured to switch a route between the transmission circuit and the antenna and a route between the reception circuit and the antenna, characterized in further comprising: an impedance circuit configured to have a higher impedance than an impedance of the antenna; a second switching circuit; a third switching circuit; and a fourth switching circuit, wherein the second switching circuit is configured to switch conduction and non-conduction between the fourth switching circuit and the transmission circuit, the third switching circuit is configured to switch conduction and non-conduction between the fourth switching circuit and the reception circuit, and the fourth switching circuit is configured to switch conduction and non-conduction between the impedance circuit and both of the second switching circuit and the third switching circuit. an impedance circuit configured to have a higher impedance than an impedance of the antenna; a second switching circuit; a third switching circuit; and a fourth switching circuit, wherein the second switching circuit is configured to switch conduction and non-conduction between the fourth switching circuit and the transmission circuit, the third switching circuit is configured to switch conduction and non-conduction between the fourth switching circuit and the reception circuit, and the fourth switching circuit is configured to switch conduction and non-conduction between the impedance circuit and both of the second switching circuit and the third switching circuit.