PURPOSE: To improve efficiency by driving a brake motor for high speed operation, which utilizes magnetic attraction force due to motor field flux to release a brake, at an inverter output frequency higher than a commercial power supply frequency when an electric hoist is not hanging a load.

CONSTITUTION: A brake motor utilizing magnetic attraction force due to motor field flux to release a brake is provided with two kind voltage switching type stator coils 4. The connection of the stator coils 4 is switched by a coil connection switch 35. An output pattern is set by an inverter 34 so that, when a working frequency exceeds at least an output frequency fd at which the brake starts to operate, output voltage Vh becomes Vh>fd/fh.V2 at a maximum output frequency of fh in relation to low frequency commercial voltage V2. In addition, at least, in hoisting up and down while an electric hoist is not hanging a load, the mode of the inverter 34 is switched into the pattern mentioned above, and the stator coil 4 is switched to the low voltage connection side by a speed switching circuit 38 respectively.