<p>An upper electrode sheet (1) having a transparent electrode formed on a transparent film of polyethylene terephthalate and a lower electrode sheet (2) having a transparent electrode formed on a transparent film of polycarbonate are arranged opposite to each other via a plurality of spacers (3) of an insulating substance between the electrodes, with a transparent hold plate (5) of a polycarbonate plate being bonded over an entire face to a lower face of the lower electrode sheet (2) via a transparent adhesion layer (4). <IMAGE></p>
