Patent ID: 7580439

Claim:
A gas laser oscillator comprising: a discharge part for exciting laser gas; an air blower for blowing the laser gas; a laser gas flow pipe constituting a circulation route of laser gas between the discharge part and the air blower; a driving part for driving the air blower; a divide wall separating the air blower and the driving part; a gas supply apparatus having at least one valve, and supplying laser gas to the laser gas flow pipe; a main ejection apparatus having at least one valve and ejecting laser gas out from the laser gas flow pipe; a sub ejection apparatus having a pipe ejecting the laser gas from the driving part of the air blower; a detector for detecting an amount of laser gas flowing through the laser gas flow pipe; a controller controlling each valve of the gas supply apparatus and the main ejection apparatus; and a clogged laying pipe judge part judging the pipe of the sub ejection apparatus to be clogged when the detected amount of the laser gas is smaller than a predetermined value, wherein a signal from the detector is input to the controller; and wherein the controller compares the amount of the laser gas which is detected at a time the valve of the main ejection apparatus is closed, with a predetermined value.