The temperature of a stator coil is measured by a temperature sensor (14), amplified by a stator coil temperature amplifier (21), and transmitted to a vehicle control section (23). Further, motor cooling oil (17) for cooling the outer periphery of the stator cools the stator coil (16) along an end coil section of the stator coil (16). The temperature of the motor cooling oil raised by the stator coil (16) is measured by a temperature sensor (15) and transmitted also to the vehicle control section (23) via a motor cooling oil temperature amplifier (22). The vehicle control section (23) estimates the temperature of a rotor magnet based on a thermal model (relationship between temperature, a heat production amount, and heat resistance) of the motor cooling oil, the stator coil, and the rotor magnet by using the motor cooling oil temperature and the stator coil temperature as input values and sends a control instruction to a motor control section (24).