PURPOSE: To make possible provision of a reference electrode in proximity to display electrodes and enable intricate patterns to be readily realized as well by providing the reference electrode between the display electrodes and counter electrode.

CONSTITUTION: Electrolyte 13 is sealed between a transparent glass substrate 11 which is provided with a counter electrode 16 composed of a transparent conductive film 14 and an EC material 15 and a transparent glass substrate 12 which is provided with display electrodes 19 composed of transparent conductive films 17 and EC materials 18 and assuming specified apttern shapes. A reference electrode 20 is provided between the electrodes 16, 19 so as to cover the electrodes 16, 19 over their entire part, and further white scattering plates 21, 22 such as of white ceramics composed of white ion transmittable and insulating type scattering materials are interposed between the electrodes 16, 19 and the electrode 20 so as to hold the electrode 20 therebetween thereby fixing the electrode 20, preventing shorting between the electrode 20 and the electrodes 16, 19 and furter obviating the appearance of the electrode 20