Patent ID: 6894248

Claim:
A laser beam machining apparatus, comprising: a laser oscillator which oscillates a laser beam, the laser oscillator having a laser beam outgoing port to output the laser beam; a machining head which machines a workpiece with the laser beam; an optical duct with an optical system to guide the laser beam from the laser beam outgoing port to the machining head; a purge gas supply port that opens into the optical duct and situated near any one of the laser beam outgoing port and the machining head, wherein a purge gas supply unit supplies purge gas into the optical duct from the purge gas supply port; a purge gas exhaust port that opens into the optical duct and situated near any one of the laser beam outgoing port and the machining head, wherein the purge gas in the optical duct is output from the purge gas exhaust port; and an odor sensor that detects undesired gas in a portion of the optical duct from the laser beam outgoing port to the machining head, wherein the undesired gas is a gas that makes the laser beam anomalous.