A humidifier including a spray unit configured to apply electric charge to water, and to spray water having electric charge applied thereto, an evaporation unit formed with a duct in which evaporation of the electrically-charged water being sprayed is taken place, and configured to guide a vapor and a foreign substance, which are separated from each other through the evaporation, to an outside, and a dust collection unit configured to collect the foreign substance at an inside the duct by forming an electric field, the humidifier capable of performing a large-capacity humidification by the generation of the electrically charged droplets, and capable of removing the foreign substance included in the droplets by using the electrical force, thereby enhancing the cleanliness of the humidification, and by using an electric field, accelerating the evaporation so that the size of the duct is minimized, and thus manufacturing the humidifier in a compact size.