PURPOSE: To correct the operating error of an interference-preventing device for a working equipment by a simple way.

CONSTITUTION: A correction value-inputting device 25 is provided in a cab 6 of a mini-sized, swingable power shovel 1. In the case wherein a point where a bucket 16 is pivoted on an arm 15 is taken as P, a position where the point P is actually stopped by an interference-preventive control is taken as Xr, and a position where the point P is to be theoretically stopped is taken as Xc, an error of a stoppage position, =-d=Xc-Xr, is inputted into the correction value-inputting device 25. On the basis of its inputted value, a correction- processing part 26 changes the data of the position where the point P is to be stopped into (Xc+d). In this way, the position Xr where the point P is actually stopped is matched with the position Xc where the point P is to be theoretically stopped.