This ultrasonic air humidifier provides a comfortable indoor climate and removes bacteria from the air. It is easily operated, as water can be refilled from above as soon as the appropriate sensor indicates a low water level. If it is not possible for the humidifier to be immediately refilled, it automatically moves into standby mode to prevent overheating. The ambient air is analysed by the temperature and humidity sensor, with the degree of nebulisation and ventilator speed being adjusted accordingly.