Abstract: A compound surface-charging electrode (6) with a metal housing (11). The housing accommodates two or more unit electrodes and upstream resistances (1) that can be connected to a source (U) of high voltage. The unit electrodes have prongs (3) that project out of the housing. The housing is open enough to allow them to do so. Each prong can be covered up by an electrically conductive electrode hatch (4). The electrode hatch is electrically conducting and connected to the housing. The housing and the electrode hatch are connected over to one terminal of a resistor, the other terminal of which can be grounded.