Medical oxygen humidifier with heating unit designed for comfortable oxygen therapy with moisturizing close to body temperature. The device provides heating of sterile demineralized water in an individual nebulizer and allows accurate metering of the oxygen-air mixture due to the presence of a flow meter. Its own power source ensures safe contact of the heater with water. A convenient control panel allows to control the temperature of water supplied to the nebulizer, as well as monitor the current performance of the device.