An organic light emitting diode display device, comprising: a substrate; a scan line disposed on the substrate, configured to transfer a scan signal (Sn) and extending in a first horizontal direction; a data line disposed on the substrate, configured to transfer a data signal (Dm), and extending in a second vertical direction crossing the first direction; a second driving voltage line configured to transfer a driving voltage, ELVDD, the second driving voltage line including a first portion extending in the second direction, and a second portion connected to the first portion; a first driving voltage line (126, 179h, 192) positioned in a different layer from the second driving voltage line and electrically connected to the second driving voltage line, a switching thin film transistor including a first gate electrode connected to the scan line, a first source electrode connected to the data line, and a first drain electrode facing the first source electrode; a driving thin film transistor including a second source electrode directly connected to the first drain electrode, a second drain electrode facing the second source electrode, a second gate electrode (G1, 125a) and a semiconductor; a storage capacitor (Cst) including the second gate electrode of the driving thin film transistor as a first electrode and the second portion of the second driving voltage line as a second electrode; and an organic light emitting diode, OLED, electrically connected to the second drain electrode of the driving thin film transistor via a transistor, characterized in that the semiconductor of the driving thin film transistor has a reverse ' ' shape, and the second electrode of the storage capacitor (Cst) overlaps the second gate electrode (G1, 125a) and the whole reverse ' ' shape portion of the semiconductor of the driving thin film transistor, wherein the second driving voltage line is extended in a vertical direction, and connected with the first driving voltage line through a first contact hole 161, the first driving voltage line (126, 179h, 192) transfers the driving voltage ELVDD in a horizontal direction, and the second driving voltage line transfers driving voltage ELVDD in the vertical direction, the second portion of the second driving voltage line is an expanded region, and one expanded region is formed for each pixel, the expanded region of the second driving voltage line forms the second electrode of the storage capacitor (Cst), the driving voltage ELVDD is applied to the second electrode of the storage capacitor (Cst), the storage capacitor (Cst) includes the gate electrode of the driving thin film transistor, the second electrode of the storage capacitor (Cst), and an interlayer insulating layer therebetween. a substrate; a scan line disposed on the substrate, configured to transfer a scan signal (Sn) and extending in a first horizontal direction; a data line disposed on the substrate, configured to transfer a data signal (Dm), and extending in a second vertical direction crossing the first direction; a second driving voltage line configured to transfer a driving voltage, ELVDD, the second driving voltage line including a first portion extending in the second direction, and a second portion connected to the first portion; a first driving voltage line (126, 179h, 192) positioned in a different layer from the second driving voltage line and electrically connected to the second driving voltage line, a switching thin film transistor including a first gate electrode connected to the scan line, a first source electrode connected to the data line, and a first drain electrode facing the first source electrode; a driving thin film transistor including a second source electrode directly connected to the first drain electrode, a second drain electrode facing the second source electrode, a second gate electrode (G1, 125a) and a semiconductor; a storage capacitor (Cst) including the second gate electrode of the driving thin film transistor as a first electrode and the second portion of the second driving voltage line as a second electrode; and an organic light emitting diode, OLED, electrically connected to the second drain electrode of the driving thin film transistor via a transistor, characterized in that the semiconductor of the driving thin film transistor has a reverse ' ' shape, and the second electrode of the storage capacitor (Cst) overlaps the second gate electrode (G1, 125a) and the whole reverse ' ' shape portion of the semiconductor of the driving thin film transistor, wherein the second driving voltage line is extended in a vertical direction, and connected with the first driving voltage line through a first contact hole 161, the first driving voltage line (126, 179h, 192) transfers the driving voltage ELVDD in a horizontal direction, and the second driving voltage line transfers driving voltage ELVDD in the vertical direction, the second portion of the second driving voltage line is an expanded region, and one expanded region is formed for each pixel, the expanded region of the second driving voltage line forms the second electrode of the storage capacitor (Cst), the driving voltage ELVDD is applied to the second electrode of the storage capacitor (Cst), the storage capacitor (Cst) includes the gate electrode of the driving thin film transistor, the second electrode of the storage capacitor (Cst), and an interlayer insulating layer therebetween.