Abstract: A device for electrophoresis applies a voltage to a medium in contact with a plurality of electric conductors so that a potential of adjacent conductors is within a certain range. This allows preventing decline in electrophoresis speed. A device for electrophoresis and transfer includes an electrode having a plurality of electrode regions being insulated one another and arranged in a specific direction. This allows providing a practical and easy-to-use device for electrophoresis and transfer. A device for transfer alters an applied voltage or applied voltage duration to a certain position to another position. This allows improving transfer efficiency.