PURPOSE: To make deburring operation efficient and prevent a deburring tool from being overloaded.

CONSTITUTION: When a large burr is encountered nearby a point P'1 on an instruction track and a cutting resistance monitor value exceeds a threshold value Xth, the robot is brought under turnout/return control according to patterns illustrated by (I)-(III). When the cutting resistance monitor value of the deburring tool exceeds a specific value, the tool is put on the track which extends from the point P'1 to a turnout point Q1 and then to an instruction point P2 again or other return target points P'2 and P'3. If the cutting resistance monitor value (x) exceeds the Xth again at halfway points Q2 and Q2 on the return track, the tool moves to the points Q3 and Q3 again and then to return target points P2, P"2, and P'3. The turnout point is designated using a component of turnout vector (q) in a specified coordinate system. The cutting resistance monitor value is utilized for moving speed control over the robot in addition to turnout/return control. The cutting resistance monitor value is collated with an override chart specified with a polygonal function and an override value is controlled to obtain a robot moving speed corresponding to the difficulty of deburring.