A laser processing apparatus includes a six-axis robot operating by robot axes controlled by a robot control device and a processing tool mounted on the end of the arm of the robot. A processing head is provided on a horizontal movement mechanism provided on a horizontal movement mechanism support base, which is in turn supported by a carrier able to move on a vertical movement mechanism. The vertical movement mechanism and the horizontal movement mechanism are driven by additional axes controlled by the robot control device. In a non-processing section of the workpiece etc., only the additional axes are operated to move the processing head at a high speed and shorten the cycle time. When operating the additional axes to move, the data of the relative position of the control point (tool end point) with respect to a fixed point on the arm forward end is corrected each time.