PURPOSE: To operate a brake very smoothly by controlling the power generation state of an induction machine which serves as a power generator driven by wheels, and providing an induction machine control means for reducing the power-generation capability of the induction machine when a wheel rotation detection means detects the lock state of the wheels.

CONSTITUTION: An induction machine 20 coupled to the wheels 1 to 4 of a vehicle is controlled as a power generator to apply brake force to the wheels 1 to 4. When it is determined that the wheels 1 to 4 are locked, an induction machine 20 control means 23 restrains the amount of power generated by the induction machine 20 to reduce brake force to unlock of the wheels 1 to 4. Regenerated power is charged in a charge means. This constitution allows very smooth brake operations, detailed braking control, and efficient recovery of energy obtained from braking.