Abstract: An electric control apparatus for an industrial robot the arm of which is actuated to carry out machining of a workpiece by means of a machining tool attached thereto. The control apparatus includes a force sensor arranged to detect reaction force acting on the tool, a memory for memorizing a maximum reaction force detected by the sensor during each machining process of the workpiece in a plurality of split sections of a teaching line, a comparator for comparing the memorized maximum reaction force with a set value indicative of a limit of reaction force acting on the tool and for producing a signal therefrom when the memorized maximum force exceeds the set value.