PURPOSE: To protect the environment from being affected by introducing, into a deodorizing device, the dust and gas dispersed by air injection and thereby removing the odor of gas or the dust.

CONSTITUTION: A laser beam 1 is emitted from the light source of an irradiating device, and operated along a robot frame 5 through a belt 7 and a roller 8. An air injection device 6 is fixed on the operating member 9. With an injection nozzle 10 provided on the tip end of a chevron-shaped pipe 11 and with an elbow 12 on the rear end, they are connected to a compressed air source 18 through piping 19. A work 21 is irradiated with the laser beam 1 and is engraved while the irradiated part is injected with air 17. Simultaneously, the dust and gas generated by the irradiation of the laser are blown off and dispersed from the working part by the injection of air 17, and introduced into a deodorizing device 24 through an inlet port 23 removing the dust and the odor of the gas. Thus, the engraving of a rubber stamp is performed efficiently with a laser beam.