Abstract: A laser processing apparatus which is high in production efficiency, and capable of easily and automatically changing processing heads from one to another according to the type of the thermal processing to be done is disclosed. The laser processing apparatus includes a plurality of processing heads composed of a processing head for cutting work, a processing head for welding work and a processing head for hardening work. The laser processing apparatus moves one processing head toward a processing position with respect to the frame having a laser beam generator by a processing head driving unit. The apparatus includes a workpiece moving system for moving a workpiece with respect to the processing head positioned in the processing position. Therefore, a compact laser processing apparatus, high in production efficiency, and which is capable of selecting an optimum processing head from processing heads according to the type of the thermal processing to be done, results.