Abstract: An electrode structure for use with medical electronics instruments such as electromyographs is described. A thin, flexible body of non-conductive material has one or more wells therein. A flexible conductive member which provides an electrode is disposed at the bottom of each well. The spacing between a plurality of electrodes, which can provide bipolar and ground inputs to the medical electronic instrument, is precisely determined by virtue of the disposition of the electrodes in the wells. The electrode structure provides contact with a body surface, usually the skin. To facilitate the contact a conductive jelly is used. This conductive jelly is received in the wells. It makes contact with the electrodes. Ribs are provided in the regions between the electrodes which form a seal at the skin so as to prevent the flow of conductive fluid between electrodes; thus preventing short circuits.