A laser chamber of a discharge-excitation-type gas laser apparatus may include a container which contains laser gas therein; a pair of discharge electrodes arranged in the container; a cross flow fan configured to supply the laser gas to a discharge space between the discharge electrodes, the cross flow fan including a rotation shaft with which the cross flow fan rotates in a predetermined rotation direction and a plurality of blades, each longitudinal direction of which is parallel to an axial direction of the rotation shaft; and a stabilizer arranged outside a rotation trajectory of the cross flow fan, and arranged such that a difference between a maximum position and a minimum position of an end portion in the rotation direction on a side opposite to the rotation direction is larger than 0 and is smaller than an interval of two blades adjacent to each other among the plurality of blades.