The objective is to obtain an orthogonal excitation-type gas laser oscillation device which is small in size and has high-output, by raising the capability thereof to cool a laser medium gas. The orthogonal excitation-type gas laser oscillation device comprises a discharge unit having a pair of discharge electrodes, axial blowers, each having a plurality of moving blades operated by a permanent-magnet-type motor, a first heat exchanger, whereof a plurality of cooling fins are disposed in planes that are orthogonal to the optical axis, a second heat exchanger, whereof a plurality of cooling fins are disposed in planes that are orthogonal to the optical axis, and a gas duct constructed between the discharge unit and the first heat exchanger, wherein the axial blowers are disposed in a gas passage. The axial blowers are disposed on the upstream side of the first heat exchanger. The second heat exchanger is disposed on the upstream side of the axial blowers.