A control apparatus includes: a rotor temperature estimation unit estimating a temperature of a rotor based on stator temperature information from a first temperature sensor for identifying a temperature of a stator, refrigerant temperature information from a second temperature sensor for identifying a temperature of refrigerant used to cool an electric motor, and rotation speed information about the rotor from a resolver for identifying a rotation speed of the rotor; and an electric motor control unit controlling at least one of an output characteristic and a drive condition of the electric motor based on the temperature of the rotor estimated by the rotor temperature estimation unit.