An air-conditioning device conditioning air in an indoor space, the device comprising: an indoor unit drawing indoor air, adjusting a temperature of the indoor air drawn, and expelling the indoor air into the indoor space; a suction air temperature sensor provided in the indoor unit to measure the temperature of the indoor air drawn into the indoor unit; a wireless temperature sensor unit separate from the indoor unit, the wireless temperature sensor unit including an ambient temperature sensor and a transmitter, the ambient temperature sensor measuring an ambient temperature, the transmitter transmitting a signal of a measurement value of the ambient temperature sensor by radio; a receiving section receiving the signal transmitted by the transmitter; an abnormal condition determining section determining whether or not the wireless temperature sensor unit is in an abnormal condition; an index setting section setting a temperature index value serving as an index of indoor temperature; and a controller (28, 66) controlling operation of the air-conditioning device based on the temperature index value set by the index setting section, wherein while the abnormal condition determining section determines that the wireless temperature sensor unit is in the abnormal condition, the index setting section determines a measurement value of the suction air temperature sensor to be the temperature index value, characterized in that the abnormal condition determining section is configured to, if an absolute value of a difference between the measurement value of the suction air temperature sensor and the measurement value of the ambient temperature sensor is greater than or equal to a predetermined temperature difference threshold (ΔTth), and/or if the measurement value of the suction air temperature sensor is less than or equal to a predetermined first temperature threshold or greater than or equal to a predetermined second temperature threshold greater than the first temperature threshold, determine that the wireless temperature sensor unit is in the abnormal condition. an indoor unit drawing indoor air, adjusting a temperature of the indoor air drawn, and expelling the indoor air into the indoor space; a suction air temperature sensor provided in the indoor unit to measure the temperature of the indoor air drawn into the indoor unit; a wireless temperature sensor unit separate from the indoor unit, the wireless temperature sensor unit including an ambient temperature sensor and a transmitter, the ambient temperature sensor measuring an ambient temperature, the transmitter transmitting a signal of a measurement value of the ambient temperature sensor by radio; a receiving section receiving the signal transmitted by the transmitter; an abnormal condition determining section determining whether or not the wireless temperature sensor unit is in an abnormal condition; an index setting section setting a temperature index value serving as an index of indoor temperature; and a controller (28, 66) controlling operation of the air-conditioning device based on the temperature index value set by the index setting section, wherein while the abnormal condition determining section determines that the wireless temperature sensor unit is in the abnormal condition, the index setting section determines a measurement value of the suction air temperature sensor to be the temperature index value, characterized in that the abnormal condition determining section is configured to, if an absolute value of a difference between the measurement value of the suction air temperature sensor and the measurement value of the ambient temperature sensor is greater than or equal to a predetermined temperature difference threshold (ΔTth), and/or if the measurement value of the suction air temperature sensor is less than or equal to a predetermined first temperature threshold or greater than or equal to a predetermined second temperature threshold greater than the first temperature threshold, if an absolute value of a difference between the measurement value of the suction air temperature sensor and the measurement value of the ambient temperature sensor is greater than or equal to a predetermined temperature difference threshold (ΔTth), and/or if the measurement value of the suction air temperature sensor is less than or equal to a predetermined first temperature threshold or greater than or equal to a predetermined second temperature threshold greater than the first temperature threshold, determine that the wireless temperature sensor unit is in the abnormal condition.