An organic electroluminescent display (ELD) device having a first substrate having an array element layer and a second substrate having an organic electroluminescent diode includes a gate line formed on the first substrate, a data line formed on the first substrate, a power supply line spaced apart from the data line and formed on the first substrate, the power supply line being formed with same material as the gate line in a same process as the gate line, a switching thin film transistor having a semiconductor layer formed of amorphous silicon, a driving thin film transistor formed near a crossing portion of the switching thin film transistor and the power supply line, a connecting electrode connected to the driving thin film transistor and an electrical connecting pattern for electrically connecting the connecting electrode to the organic electroluminescent diode.