To provide a control system for a permanent magnet motor which enables stoppage of the motor in a short time, even if an inverter fails or the power is shut down.

The control system is constituted of a first switch provided on the output side of the inverter, a resistor connected serially with a second switch provided between the first switch, and a capacitor connected directly with a third switch. When the dynamic brake of the motor is applied to and the brake only of the resistor is short for braking, the braking force is covered by controlling the terminal voltage of the motor to be increased to set it as flux field.