The invention relates to a device and method for electrolytically treating flat work pieces (1), more especially for electrolytically treating electrically conductive structures S that are electrically insulated against each other on the surfaces of the work pieces. The method comprises conveying and processing the work pieces (1) on the conveying paths T′, T″ in the device, said device comprising at least one assembly A located between tow conveying paths, said assembly including a first and a second rotatable contacting electrode (2, 8) with the contacting electrodes being associated each with one of the conveying paths, and first contacting electrodes (2) abutting against the work pieces being conveyed in a first conveying path T′, and being spaced from the second conveying path T″ and second contacting electrodes (8) abutting against the work pieces being conveyed in the second conveying path T″ and being spaced to the first conveying path T′. The assembly and the work pieces are brought into contact with the treatment liquid. The contacting electrodes comprise first and second segments (9, 10) each that are insulated against each other and that are contacted to a current source (5) in such a manner that electrolysis areas E are formed between the work piece (1) being conveyed on the first and second conveying paths T′, T″, respectively, and second segments (9) that are turned towards the first and second conveying paths T′, T″ respectively and are not contacting the work pieces (1).