PURPOSE: To improve the efficiency of workability by performing the high speed hoist-up (hoist-down) securely at the time of non-load in a hoist to be controlled by an inverter.

CONSTITUTION: A two-stage action type push button switch is used for a push button switch 2 for operating the hoist-up (hoist-down) of a hoist, and the hoist is operated at a low speed by the first stage action, and operated at an intermediate speed for several seconds by the second stage action, and during this intermediate speed operation, a detected current value of an inverter and a preset non-load current value are compared with each other, and in the case where the detected value is smaller than the preset value, the hoist is operated at a high speed, and in the case where the detected value is larger than the preset value, the hoist is operated at a rated speed.