JPH033552B

PURPOSE:To remove smoke, to fix a work and to improve machining accuracy by providing, to a flat work, a fan for ganerating a parallel flow and a vertical flow pushing down the work on a supporting rest. CONSTITUTION:A fan 7 on the upstream side and a fan 8 on the down-stream side in a blower 6 are driven to generate a parallel flow A on the upper part of a cloth 2 supported on a mesh conveyor 12 and an exhauster 11 is driven to suck part of the outside air B introduced by an upstream fan 7 from a suction hood 13 and to generate a downward vertical flow D on the surface of the cloth 2. Then, a laser beam machine is driven to project laser beam on the cloth 2 on the mesh conveyor 12 from a mirror 3. At this time, smoke is generated from the working part of the cloth 2 but removed at once by the parallel flow A and the vertical flow D. In addition, the cloth 2 is fixed by the wind pressure of the vertical flow D on the mesh conveyor 12.