A device comprising a group of electrode elements (A, B) for a condenser separator of a two-step electrofilter which group of electrode elements comprises at least two electrode elements (A, B) each consisting of two different polymers, wherein a. the electrode elements (A, B) are provided in the form of thin strips or groups of flat sheets, b. a core constitutes a major layer of the electrode elements (A, B), c. at least one current conductive element (M2, M2', M2") is provided on a front side of the electrode elements (A, B), either in the form of a polymer arranged as a coating on the core of the electrode elements (A, B), or embedded in said core, d. the extension of the at least one current conductive element is smaller than the extension of the core along both the width and the depth thereof, e. a first portion (M1, M3, M3') of a back side of the electrode element that is opposite the first side of the electrode element and arranged closest to an adjacent second electrode element is formed of a polymer having a surface resistivity of more than 1×10 12 ohm/sq and preferably more than 1×10 14 ohm/sq, f. a second portion of the electrode elements (A, B) is comprised of the current conductive elements (M2, M2', M2"), characterised in that g. the electrode elements (A, B) are off-set with respect to each other in such a way that two adjacent electrode elements (A, B) do not have current conductive elements (M2, M2', M2") located at the same corresponding position, h. a current conductive element on a first side of a first electrode element is located at a first distance from the first edge of the electrode element and farther away from the second edge of the electrode element, and a current conductive element on an adjacent second electrode element is located at the first distance from the second edge of the electrode element and farther away from the first edge of the electrode element. a. the electrode elements (A, B) are provided in the form of thin strips or groups of flat sheets, b. a core constitutes a major layer of the electrode elements (A, B), c. at least one current conductive element (M2, M2', M2") is provided on a front side of the electrode elements (A, B), either in the form of a polymer arranged as a coating on the core of the electrode elements (A, B), or embedded in said core, d. the extension of the at least one current conductive element is smaller than the extension of the core along both the width and the depth thereof, e. a first portion (M1, M3, M3') of a back side of the electrode element that is opposite the first side of the electrode element and arranged closest to an adjacent second electrode element is formed of a polymer having a surface resistivity of more than 1×10 12 ohm/sq and preferably more than 1×10 14 ohm/sq, f. a second portion of the electrode elements (A, B) is comprised of the current conductive elements (M2, M2', M2"), characterised in that g. the electrode elements (A, B) are off-set with respect to each other in such a way that two adjacent electrode elements (A, B) do not have current conductive elements (M2, M2', M2") located at the same corresponding position, h. a current conductive element on a first side of a first electrode element is located at a first distance from the first edge of the electrode element and farther away from the second edge of the electrode element, and a current conductive element on an adjacent second electrode element is located at the first distance from the second edge of the electrode element and farther away from the first edge of the electrode element.