Gas laser device having function for discriminating type of alarm

A gas laser device having a function for properly controlling the gas pressure of a laser oscillator after an alarm is generated. A controller of the laser device has an alarm monitoring part which monitors as to whether an alarm is generated in the oscillator, by which discharge in the oscillator should be stopped; an alarm judging part which discriminates a type of the alarm generated in the oscillator; a gas pressure controlling part which controls a pressure of laser gas within a discharge tube of the oscillator; and a power supply controlling part which controls a power supply of the oscillator. The gas pressure controlling part controls the pressure of the laser gas within the discharge tube to an appropriate value, after the alarm is generated, based on one of a plurality of control patterns predetermined corresponding to the respective types of the alarm.