The purpose of the present invention is to provide a dust collector, an electrode selection method for a dust collector, and a dust collection method such that it is possible to select a suitable wire mesh to be used in a collecting electrode and thereby improve the collecting efficiency even at high flow velocities. A dust collector has a discharge electrode to which a voltage is applied, and a collecting electrode that is disposed facing the discharge electrode and has a planar member formed of a wire mesh, wherein the wire mesh of the planar member satisfies equations and below, and the gas face velocity (v) of the gas penetrating the wire mesh is v=0.1 m/s or higher. IndexT=(the inter-wire distance÷2)÷the opening ratio÷the wire diameter×the gas face velocity IndexT≦2.