A respiratory mask for controlling a body temperature of a patient by using a respiratory gas includes a controller for generating the respiratory gas, a gas transfer tube for receiving the respiratory gas and transferring the respiratory gas to a respiratory unit, a heat transfer metallic body configured to connect to the gas transfer tube and for cooling or heating the respiratory gas passing through the gas transfer tube, a thermoelectric element for performing an exothermic reaction or an endothermic reaction to heat or cool the heat transfer metallic body, a power supply unit configured to be located to be parallel to a bottom end of the gas transfer tube and for supplying power to the thermoelectric element via the controller, and a respiratory unit configured to connect to the gas transfer tube and for supplying the respiratory gas passing through the gas transfer tube to a patient.