Abstract: The gas circulation loop for a laser discharge tube includes a gas supply duct (a) and a gas exhaust duct (c), wherein the gas supply duct (a) and/or the gas exhaust duct (c) is elongated in the longitudinal direction of the laser discharge tube (b) and connected to the laser discharge tube (b) by an inlet flow distributor and, respectively an outlet flow distributor, adapted for controlled transversal gas inlet and, respectively outlet, over at least part of the laser discharge tube (b), and wherein the inlet flow distributor and/or the outlet flow distributor include a plurality of respective inlet channels or outlet channels, characterized in that the ratio between the diameter of the gas supply duct (a) and the diameter of the inlet channels, and/or the ratio between the diameter of the gas exhaust duct (c) and the diameter of the outlet channels is at least 2. A laser apparatus including such gas circulation loop is also described.