Abstract: A device for collecting dust using highly charged hyperfine liquid droplets formed through an electro-hydrodynamic atomization process is disclosed. In the dust collecting device of this invention, a high voltage is applied to capillaries, set within a dust guide duct and having nozzles at their tips. An electric field is thus formed between the capillaries and the duct, and allows the nozzles to spray highly charged hyperfine liquid droplets. Such liquid droplets absorb dust laden in air, flowing in the duct by suction force of a fan. An electrostatic dust collector is detachably coupled to the duct while being insulated from the duct, and forms an electric field having polarity opposite to that of the highly charged liquid droplets, thus electrostatically collecting and removing the dust absorbed by the highly charged liquid droplets. The dust collecting device of this invention easily and effectively removes fine dust having a size smaller than 0.1 cm.