Abstract: An apparatus, which collects particulate matter contained in a gas flowing through a flow path formed in a cylindrical shape having an outer surface and an inner surface, includes: an outer shell that forms the outer surface of the flow path; a ground electrode that forms the inner surface of the flow path; a filter layer that is arranged between the outer shell and the ground electrode; and a discharge electrode that generates, when a voltage is applied, an ion wind inducing a secondary flow toward the ground electrode in a direction transverse to the flow path. The secondary flow passes through the ground electrode and the filter layer having a predetermined aperture ratio.