An electric precipitator to collect contaminants, such as dust, using electrical attraction. The electric precipitator includes high-voltage electrode plates and low-voltage electrode plates alternately stacked to form an electrification region and a collection region in an air flow direction, wherein each of the high-voltage electrode plates includes a discharge electrode to generate discharge between the discharge electrode and an opposite electrode so that contaminants are electrified in the electrification region and a collection electrode disposed over the electrification region and the collection region to collect the electrified contaminants in the collection region.