A heat generating unit is incorporated in a mask in order to actively supply warm steam, and also drug vapor, to the nose and throat, and moisturize the upper respiratory tract. It is preferable that a metal powder, salt, and water be contained in the heat generating unit, and that an exothermic composition that releases steam in conjunction with the oxidation reaction of the metal powder be used therein. It is preferable that either an inhalation valve or exhalation valve be provided in the main mask body.