This laser oscillation device is provided with: a refrigerant container; at least one cartridge, which is attached to the refrigerant container, and which includes a laser gain medium and an incidence path section for guiding laser seed light to the laser gain medium; at least one nozzle for spraying the refrigerant to the laser gain medium, said at least one nozzle being provided in the refrigerant container; and a vacuum heat insulating container, which houses the refrigerant container inside, and forms a vacuum insulation layer on the outer peripheral side of the refrigerant container. The cartridge is removably provided with respect to the refrigerant container, said cartridge being provided in the longitudinal direction of the laser gain medium.