A rotary machine cools a cooling target inside a rotor rotatable around a rotational axis, includes a condenser section disposed outside the rotor and condenses a gas phase cooling medium into a liquid phase cooling medium; an evaporator section disposed inside the rotor, and evaporates the liquid phase cooling medium generated by condensation in the condenser section into the gas phase cooling medium, by heat exchange between the cooling target and the liquid phase cooling medium; and a coupling pipe flows the liquid phase cooling medium and the gas phase cooling medium between the evaporator section and the condenser section, wherein the coupling pipe has a pipe structure in which a liquid phase cooling medium passage flows the liquid phase cooling medium generated by the condensation in the condenser section and a gas phase cooling medium passage flows the gas phase cooling medium generated by evaporation in the evaporator section.