The invention provides an electric dust collector. A dust-collecting device of the electric dust collector comprises a structure configuring a primary filter (21) configured in the following manner: in the primary filter (21) provided with a plurality of through holes penetrating through an upstream side surface and a downstream side surface of the primary filter (21), a direction of a central axis and a forward direction of an outer side swirling airflow (61) flowing on the upstream side surface of the primary filter (21) form a second inclined angle which is downward inclined opposite to the forward direction. The central axis is a straight line of connecting an opening center of a first etching hole and an opening center of a second etching hole. Therefore, a declining swirling airflow (61) going toward a direction of a dust-collecting chamber (33) can be generated in the inner circumference of the primary filter (21), so that the dust can be prevented from flying; and blockage of the filter can be prevented.