A control apparatus for a load device mounted on a vehicle is provided with: a temperature sensor detecting a temperature of an inverter; a voltage sensor detecting an applied voltage of the inverter; and a control unit operating the inverter in a case where the applied voltage is a predetermined upper limit value or lower whereas stopping the inverter in a case where the applied voltage is higher than the upper limit value based on a voltage detection result by the voltage sensor. The control unit sets the upper limit value based on temperature dependency of a withstand voltage of an IGBT element included in the inverter and a temperature detection result by the temperature sensor.