Abstract: An electrostatic precipitator is disclosed. The precipitatior comprises a conduit for the passage of particles in an air flow and means generating an electrostatic field substantially orthogonal to the air flow, and an ion supply, capable of charging said particles, in which the generating means comprise a point electrode and a two dimensional surface electrode, characterised in that the plane surface electrode comprises an ion source and the point electrode comprises a counter electrode and in that the counter electrode is earthed.