A robot control device for a robot system including: a robot having a plurality of internal drive axes; a processing head retained to a leading end of the robot and having a processing tool and a tool drive axis to move the processing tool; and an external driving mechanism having one or more external drive axes and positions the robot. The robot system causes the processing tool to make contact with a processing target and conducts predetermined processing on the processing target. The control device controls the internal and external drive axes to position the processing head at a target position and controls the tool drive axis to make the processing tool make contact with the processing target, and the robot control device detects contact between the processing tool and the processing target by monitoring torque of the internal drive axis, the tool drive axis and the external drive axis.