1. A method for separating polynucleotides in a sample solution comprising the steps of; immobilizing individually different probes complementary to a plurality of target polynucleotides onto a plurality of cells formed at different regions on a single polynucleotide capturing support having an electrode on a surface of each of the cells, adding the sample solution to the surface of the support and covering the surface of each cell with the sample solution, for capturing the target polynucleotides onto said polynucleotide capturing support by a hybridization reaction, and supplying an electric field onto the electrode of each cell separately to elute the hybridized target polynucleotides from the cells individually.