An air conditioner comprising: a power conversion circuit (2, 102,103) to convert alternating-current power into direct-current power; a drive circuit (104, 105, 108) to convert the direct-current power into alternating-current power, to supply the alternating-current power to a load (3, 6), and to control an operation of the load (3, 6); a temperature detection unit (4, 5) to detect a shell temperature of the load (3, 6) and to output a detection value based on the shell temperature; a conversion circuit (115, 116, 116a) to convert the detection value into a first voltage value; a comparator circuit (114, 118) to compare the first voltage value with a second voltage value that is a threshold voltage, and to output a control signal based on a potential difference between the first voltage value and the second voltage value; and a control voltage supply circuit configured to generate a control voltage to be supplied to the drive circuit (104, 105, 108) using the direct-current power, and to control supply of the control voltage to the drive circuit (104, 105, 108) on a basis of the control signal, wherein the load is a motor, and the control voltage supply circuit is configured such that on a basis of a shell temperature of the motor, driving of the motor is stopped by cutting off the supply of the control voltage to the drive circuit (104, 105, 108), or the motor is driven by supplying the control voltage to the drive circuit (104, 105, 108), wherein the conversion circuit (115, 116, 116a) outputs the first voltage value to an outdoor unit control unit that controls an operation of an outdoor unit (400a, 400c) on which the motor is mounted, and the comparator circuit(114, 118). a power conversion circuit (2, 102,103) to convert alternating-current power into direct-current power; a drive circuit (104, 105, 108) to convert the direct-current power into alternating-current power, to supply the alternating-current power to a load (3, 6), and to control an operation of the load (3, 6); a temperature detection unit (4, 5) to detect a shell temperature of the load (3, 6) and to output a detection value based on the shell temperature; a conversion circuit (115, 116, 116a) to convert the detection value into a first voltage value; a comparator circuit (114, 118) to compare the first voltage value with a second voltage value that is a threshold voltage, and to output a control signal based on a potential difference between the first voltage value and the second voltage value; and a control voltage supply circuit configured to generate a control voltage to be supplied to the drive circuit (104, 105, 108) using the direct-current power, and to control supply of the control voltage to the drive circuit (104, 105, 108) on a basis of the control signal, wherein the load is a motor, and the control voltage supply circuit is configured such that on a basis of a shell temperature of the motor, driving of the motor is stopped by cutting off the supply of the control voltage to the drive circuit (104, 105, 108), or the motor is driven by supplying the control voltage to the drive circuit (104, 105, 108), wherein the conversion circuit (115, 116, 116a) outputs the first voltage value to an outdoor unit control unit that controls an operation of an outdoor unit (400a, 400c) on which the motor is mounted, and the comparator circuit(114, 118).