Abstract: An apparatus for gas purification is provided by means of charge build-up in an ionization means and subsequent electrostatic separation of ionized dirt particles in a separation means, which comprises collection surfaces arranged along lanes which are passed by the gas flow. These lanes are formed between fixed voltage-carrying plates and rotatable, grounded discs. The plates and the discs have substantially the same spacing to one another where a substantially stationary cleaning means strips off the deposited dirt particles on the discs. The arrangement provides an operation essentially independent of the contaminant or pollutant, high efficiency and uncomplicated production.