In a gas laser device, a laser gas sealingly stored in a chamber is excited using a discharging electrode that is electrically discharged. Laser light produced by the electrical discharging is totally reflected by a total reflection mirror. An output window partially reflects the laser light and outputs a portion of the laser light reflected between the total reflection mirror and the output window. A blower circulates the laser gas within the chamber so that the laser gas passing an electrical discharging region of the discharging electrode is circulated in the chamber and is returned to the electrical discharging region of the discharging electrode. The blower is operated according to the state of electrical discharging from the discharging electrode. The blower operation includes operating rotation of the blower in a stand-by state in which no laser gas is excited by the electrical discharging from said discharging electrode so that no laser light is emitted but the gas laser device is in a condition to output the laser light, and operating rotation of the blower in an in-operation state in which the laser gas is excited by the electrical discharging from said discharge electrode and laser light is outputted.