Air filter with electrostatic separator

The air filter has an electrostatic separator with a high voltage electrode (9) and a low voltage electrode (7), between which the air flow (4) to be cleaned is passed. One (7) electrode forms a wall of a channel of closed cross-section for the air flow to be cleaned. The other electrode (9) is arranged in the channel so shortest distance between the inner electrode and the so-called channel wall electrode is approximately equal at all points.