The biggest feature of this humidifier is that all parts contaminated by water in the humidifier can easily be separated, cleaned and sterilized. The water tank exposed to water, the ultrasonic vibration part and the tank lid are simply separated to be easily washed. Moreover,as the water tank and its lid are made of stainless, bacteria, fungi and viruses, not removed by water-washing, can be killed with the heating and boiling method after an ultra vibration part is put in the water tank full of water and the lid is covered. It is the product which can solve the troubles of users who are very worried about the use of the contaminated humidifier. In addition, the heat on the bottom enables the humidified mist to release warmly. Accordingly, spray particles become much smaller and can spread out further without dropping the ambient temperature.