A start assisting device for a high speed reluctance motor, capable of starting the motor at a specific start disabling position where a static torque with a very small angle is present due to a phase advance. When the motor can not be started at a specific position, clock signals are supplied as gate drive signals, in place of drive signals based on a motor position detection. After starting the motor, the drive signals based on the position detection is supplied as gate drive signals, so as to drive normally the motor. Otherwise, when the motor can not be started, the drive signals based on the position detection is supplied as gate drive signals for different phases, so as to start the motor. After starting the motor, the drive signals based on the position detection are supplied as gate drive signals for corresponding phases, so as to drive normally the motor.