Abstract: A ventilating window for ventilating the interior of a building or a structure such as a vehicle in a natural and gentle manner. A ventilating window for the exhaust of air is provided with a mechanism for automatically opening a window casement when the atmospheric pressure inside the window is higher than the outside atmospheric pressure, thereby dispensing with forced exhaust using a fan or the like. A ventilating window for the supply of air is provided with a mechanism for automatically closing a window casement when the atmospheric pressure outside the window is higher than the inside atmospheric pressure, thereby preventing a strong wind from blowing into the interior. A ventilating window for both exhaust and supply of air is provided with both such opening mechanism and closing mechanism.