PURPOSE: To improve the braking performance by optionally operating a brake, grinding the surface of a lining, and dissipating the moisture absorbed in the lining via the heating by a slip when a motor is rotated at a high speed at the time of a start every morning.

CONSTITUTION: When a start button switch is pushed at the time of the start of a crane, a hoisting motor is driven in the hoisting direction via an inverter, and a brake is opened when the starting torque is generated. When a hook kicks an upper limit switch, the output of the inverter is stopped, a brake circuit is turned on via a control circuit CS, and the motor is stopped. The motor is rotated in the lowering direction via the inverter after a fixed period, the inverter is stopped by the output of a detecting relay F when the motor is confirmed to be accelerated to the rated speed, a free-running circuit is turned off for a quick brake. The surface of a brake lining is ground, and moisture is dissipated by heating.