An electroluminescence (EL) display device can include a display area with pixels (each of which can include a first electrode layer and a second electrode layer on a substrate and electroluminescence units formed between the first and second electrode layers), an electrode power supply line supplying electrode power to the display area, one or more insulating layers disposed on the electrode power supply line (including one or more via holes and containing an organic material), and a sub-conductive layer formed on the insulating layer including the via hole along the electrode power supply line. In addition, the electrode power supply line and the second electrode layer may be coupled to each other at the via hole through the sub-conductive layer. The sub-conductive layer on the insulating layer can include one or more penetration portions.