A laser chamber may include a first discharge electrode, a second discharge electrode, a fan making a laser gas flow through a discharge space between the first and second discharge electrodes, a first insulating member disposed on upstream side and downstream side of the first discharge electrode in the laser gas flow, a first metal damper member disposed on upstream side of the second discharge electrode and a second insulating member disposed on downstream side of the second discharge electrode in the laser gas flow, and a second metal damper member disposed on downstream side of the second insulating member in the laser gas flow. In a boundary portion between the second metal damper member and the second insulating member, a first discharge space side surface of the second metal damper member may be located further toward the opposite side to the discharge space than a second discharge space side surface of the second insulating member. A first corner formed by the first surface and a first side surface of the second metal damper member, the first side surface being on the side of the second insulating member, may be in contact with a second side surface of the second insulating member, the second side surface being on the side of the second metal damper member.

A gas laser, including: a semiconductor laser, an optical beam-shaping system, a pair of electrodes, a discharge tube, a rear mirror, and an output mirror. The pair of electrodes includes two electrodes. The electrodes are symmetrically disposed at an outer layer of the discharge tube in parallel. The electrodes are connected to a radio-frequency power supply via a matching network, and the electrodes operate to modify working gas in the discharge tube through radio-frequency discharge. The rear mirror and the output mirror are disposed at two end surfaces of the discharge tube, respectively. The rear mirror, taken together with the output mirror and the discharge tube, form a resonant cavity. The output mirror is configured to output a laser beam.

A gas laser oscillator includes laser gas circulation paths including first and second paths; a first discharge tube provided in the first path; a second discharge tube provided in the second path; a laser power supply for supplying a first high frequency power to the first discharge tube and supplying a second high frequency power having a different phase from the first high frequency power to the second discharge tube; and a matching unit including a first coil and a first capacitor, and a second coil and a second capacitor. Each value of the first coil, the first capacitor, the second coil, and the second capacitor is determined such that the difference between the peak value of a voltage applied to the first discharge tube and the peak value of a voltage applied to the second discharge tube falls within a predetermined range.

A gas laser oscillator includes laser gas circulation paths including first and second paths; a first discharge tube provided in the first path; a second discharge tube provided in the second path; a laser power supply for supplying a first high frequency power to the first discharge tube and supplying a second high frequency power having a different phase from the first high frequency power to the second discharge tube; and a matching unit including a first coil and a first capacitor, and a second coil and a second capacitor. Each value of the first coil, the first capacitor, the second coil, and the second capacitor is determined such that the difference between the peak value of a voltage applied to the first discharge tube and the peak value of a voltage applied to the second discharge tube falls within a predetermined range.