Gas laser oscillator capable of controlling gas pressure and gas consumption amount

A gas laser oscillator, comprising:

• a gas container for containing a laser gas;
• a first sensor for detecting a laser gas pressure in the gas container;
• a gas supply source for supplying the laser gas into the gas container;
• a vacuum pump for exhausting the laser gas from the gas container;
• a first control valve capable of controlling a supply amount of laser gas supplied into the gas container by adjusting an opening of the first control valve;
• a second control valve capable of controlling an exhaust amount of the laser gas exhausted from the gas container by adjusting an opening of the second control valve;
• and
• a controller for controlling the openings of the first control valve and the second control valve, respectively,
• the controller comprising:
• a first storage unit for storing data that indicates a relationship between the laser gas pressure in the gas container, the opening of the second control valve, and the exhaust amount of the laser gas;
• a gas pressure control unit for controlling the openings of the first control valve and the second control valve, respectively, such that the laser gas pressure in the gas container becomes closer to a reference gas pressure;
• and
• a gas consumption amount control unit for controlling the openings of the first control valve and the second control valve, respectively, such that the exhaust amount of the laser gas becomes closer to a target consumption amount.