A system was establishedfor the parallel synthesis of peptide library arrays in afully automated manner Synthesis takes place in blocks made of polyoxymethylene that hold during all synthesis steps a polypropylene membrane of 8 x 12 cm. Yields are in the nanomole range, obtained at a low consumption of reagents. The current setup is based on a commercially available pipetting robot and supports the generation of 1536 different oligomers/run. Much higher array densities are possible because the membranes are amicable to spot diameters of down to 200 microm, naturally at a cost of the absolute amount produced of each oligomer The method was put to use for the creation of arrayed libraries of peptide nucleic acids (PNAs). These can be employed both as a source of PNA molecules applied individually in experimentation subsequent to their release or as intact oligomer arrays in hybridization analyses.