A laser-oscillation cooling device includes a laser excitation unit that excites a laser beam and locally emits heat, a storage tank that is capable of storing a cryogenic liquid at an atmospheric pressure and discharge the cryogenic liquid which is evaporated, a pressurization and supply unit that pressurizes the cryogenic liquid stored in the storage tank and supplies the pressurized cryogenic liquid to the laser excitation unit, and a decompression and return unit that decompresses the cryogenic liquid which is supplied to the laser excitation unit and used to cool the laser excitation unit and returns the cryogenic liquid to the storage tank.