Abstract: A multiple electrode for measuring electro-physiological characteristics of a biological specimen includes a plurality of micro-electrode provided on a first region on a substrate, and a reference electrode provided in a second region on the substrate. The reference electrode includes at least one stimulus reference electrode for applying an electrical signal to the plurality of micro-electrodes. Preferably, the reference electrode includes at least one measurement reference electrode for detecting an electrical signal from the plurality of micro-electrodes, and the stimulus reference electrode is electrically insulated from the measurement reference electrode. Preferably, the second region is placed at a distance from an outer edge of the first region, and surrounds the first region.