The invention relates to an electrode assembly 20, in particular for applying at least one electric field to adherent cells, comprising at least two electrodes 21, each having at least one surface 32 which is arranged opposite the corresponding surface 32 of the other electrode 21, wherein an electrically insulating material 26 is arranged at least partially between the surfaces 32 of the electrodes 21. The solution according to the invention allows the electric field to be concentrated in the region of the cells to be treated such that a voltage pulse, or the current produced thereby, flows through the cells without the majority flowing away over the cells unused in the electrolyte. The invention further relates to a method for applying at least one electric field to adherent cells, in which the electric field is generated by applying a voltage to at least two electrodes, the electric field is concentrated on the side of the electrodes which faces the cells and/or is limited to the space between the cells and the side of the electrodes which faces the cells.