An organic light emitting display device comprising: a driving transistor including a semiconductor layer including an oxide semiconductor material, wherein the driving transistor is configured to drive an organic light emitting diode; a first transistor including a semiconductor layer including the oxide semiconductor material, wherein the first transistor is configured to be controlled by a scan signal (SCAN) provided from a gate line, and connected between a reference voltage line and a source electrode of the driving transistor; a second transistor including a semiconductor layer including the oxide semiconductor material, controlled by the scan signal (SCAN) commonly provided from the gate line, and connected between a data line and a gate electrode of the driving transistor; a storage capacitor connected between the gate electrode of the driving transistor and the source electrode of the driving transistor, the storage capacitor comprising: a first plate including the oxide semiconductor material, and connected to the semiconductor layer of the driving transistor and the semiconductor layer of the first transistor; an interlayer dielectric film on the first plate; a second plate positioned on the interlayer dielectric film, and connected to the semiconductor layer of the second transistor and the gate electrode of the driving transistor; a protection film on the second plate; and a pixel electrode of the organic light emitting diode, positioned on the protection film and connected to the first plate through a contact hole. a driving transistor including a semiconductor layer including an oxide semiconductor material, wherein the driving transistor is configured to drive an organic light emitting diode; a first transistor including a semiconductor layer including the oxide semiconductor material, wherein the first transistor is configured to be controlled by a scan signal (SCAN) provided from a gate line, and connected between a reference voltage line and a source electrode of the driving transistor; a second transistor including a semiconductor layer including the oxide semiconductor material, controlled by the scan signal (SCAN) commonly provided from the gate line, and connected between a data line and a gate electrode of the driving transistor; a storage capacitor connected between the gate electrode of the driving transistor and the source electrode of the driving transistor, the storage capacitor comprising: a first plate including the oxide semiconductor material, and connected to the semiconductor layer of the driving transistor and the semiconductor layer of the first transistor; an interlayer dielectric film on the first plate; a second plate positioned on the interlayer dielectric film, and connected to the semiconductor layer of the second transistor and the gate electrode of the driving transistor; a protection film on the second plate; and a pixel electrode of the organic light emitting diode, positioned on the protection film and connected to the first plate through a contact hole. a first plate including the oxide semiconductor material, and connected to the semiconductor layer of the driving transistor and the semiconductor layer of the first transistor; an interlayer dielectric film on the first plate; a second plate positioned on the interlayer dielectric film, and connected to the semiconductor layer of the second transistor and the gate electrode of the driving transistor; a protection film on the second plate; and a pixel electrode of the organic light emitting diode, positioned on the protection film and connected to the first plate through a contact hole.