A plurality of laser generators are provided to be environmentally separated from a machining station, and temperature, humidity, vibration, cleanliness and the like are detected by a sensor, and displayed. When an abnormal environment is detected, machining operation is stopped immediately or after a predetermined time elapsed. The laser generators are grouped according to each machining tool, and fiber-optic cable switching devices FC3 and FC4 are arranged for each group. By the switchover of the laser generator, and the selective connection of a fiber-optic cable by using the fiber-optic cable switching device, the degree of freedom in selecting the laser generator and the fiber-optic cable is produced. The degree of freedom is utilized according to the abnormality of the laser generator, the abnormality of the fiber-optic cable, the type of machining work, and the like, by which a machining apparatus in which the occurrence of a partial failure does not lead to long-term shutdown of a manufacturing line can be obtained.