There is described a gas laser comprising a pair of substantially mutually parallel and opposed electrodes (17, 37), between which a volume is defined containing a gas in which said electrodes generate a discharge. At opposed ends of the electrodes, in said volume, mirrors (65) are arranged to define a resonant cavity. The electrodes form an integral part of two portions (5, 7) of a sealed housing (1), containing the gas and in which the mirrors and the electrodes are housed. The two portions (5, 7) forming the housing are electrically connected.