PURPOSE: To provide a working controller for a laser beam machine capable of improving the productivity and production efficiency and also enabling an unmanned system.

CONSTITUTION: In the laser beam machine by which a work is machined to be cut by the laser beam which passes through a nozzle, a sputter detecting means which detects the sputter generated at the vicinity of the front end of the nozzle during cut machining, a deciding means which decides whether it is an adequate cutting or not from a detecting output of the sputter detecting means and a controlling means which automatically changes the cutting condition when the cutting is decided as defective and proceeds the machining under the changed condition are provided.