PURPOSE: To obtain a device which does not generate much heat and can quickly, efficiently, and evenly move samples by providing an electrode device assembly, an electrode device assembly supporting device, an electrode device assembly separating distance adjusting device, and a device for connecting the electrode device assembly to a power source.

CONSTITUTION: An electrode device assembly 12 contains external surface layers 14 which are composed of platy members made of a conductive material and layers 16 made of a material having high heat conductivity. The layers 14 work as electrodes and the layers 16 work as heat sinks. A substrate 24 supports one assembly 12 and its top face in fixed states in a state where the substrate 24 is fitted to a base section 20. The other assembly 12 is fixed to and supported by the bottom side of a separating plate 26. The separating distance between the assemblies 12 can by reduced by adjusting the distance by operating a knob 30 installed to an electrophoresis device 10 together with a supporting rod 28. Terminals 36 and 38 are used for connecting the assemblies 12 to a power source and, when the assemblies 12 are connected to the power source, the supplied power forms an electric field.