An electrode structure includes a first conductive layer, an insulation layer that covers at least a portion of a marginal area of an upper surface of the first conductive layer and has a first sloped section that slopes down toward the upper surface of the first conductive layer, a first electrode having one end formed on the first conductive layer and another end formed on the first sloped section, a third electrode that is formed on the first electrode and the insulation layer, and covers the another end of the first electrode.