A liquid crystal display device, comprising: a thin film transistor which includes: a semiconductor thin film including zinc oxide; a protection film on entirely an upper surface of the semiconductor thin film; a gate insulating film on the protection film; a gate electrode on the gate insulating film above the semiconductor thin film; and a source electrode and a drain electrode under the semiconductor thin film and electrically connected to the semiconductor thin film; the liquid crystal display device further comprising: an overcoat film covering the gate electrode; a pixel electrode on an upper surface of the overcoat film and connected to the source electrode; an auxiliary capacitor electrode disposed on an upper surface of the gate insulating film; a data line connected to the drain electrode and disposed on a same layer as that of the drain electrode;and a scanning line connected to the gate electrode and disposed on a same layer as that of the auxiliary capacitor electrode and the gate electrode, wherein the auxiliary capacitor electrode comprises a portion which includes a region overlapping the data line, a portion which is arranged near the scanning line in parallel with the scanning line, and a portion arranged along a predetermined edge of the pixel electrode, wherein a width of the portion of the auxiliary capacitor electrode including the region overlapping the data line is larger than a width of the data line. a thin film transistor which includes: a semiconductor thin film including zinc oxide; a protection film on entirely an upper surface of the semiconductor thin film; a gate insulating film on the protection film; a gate electrode on the gate insulating film above the semiconductor thin film; and a source electrode and a drain electrode under the semiconductor thin film and electrically connected to the semiconductor thin film; a semiconductor thin film including zinc oxide; a protection film on entirely an upper surface of the semiconductor thin film; a gate insulating film on the protection film; a gate electrode on the gate insulating film above the semiconductor thin film; and a source electrode and a drain electrode under the semiconductor thin film and electrically connected to the semiconductor thin film; the liquid crystal display device further comprising: an overcoat film covering the gate electrode; a pixel electrode on an upper surface of the overcoat film and connected to the source electrode; an auxiliary capacitor electrode disposed on an upper surface of the gate insulating film; a data line connected to the drain electrode and disposed on a same layer as that of the drain electrode;and a scanning line connected to the gate electrode and disposed on a same layer as that of the auxiliary capacitor electrode and the gate electrode, wherein the auxiliary capacitor electrode comprises a portion which includes a region overlapping the data line, a portion which is arranged near the scanning line in parallel with the scanning line, and a portion arranged along a predetermined edge of the pixel electrode, wherein a width of the portion of the auxiliary capacitor electrode including the region overlapping the data line is larger than a width of the data line. an overcoat film covering the gate electrode; a pixel electrode on an upper surface of the overcoat film and connected to the source electrode; an auxiliary capacitor electrode disposed on an upper surface of the gate insulating film; a data line connected to the drain electrode and disposed on a same layer as that of the drain electrode;and a scanning line connected to the gate electrode and disposed on a same layer as that of the auxiliary capacitor electrode and the gate electrode, wherein the auxiliary capacitor electrode comprises a portion which includes a region overlapping the data line, a portion which is arranged near the scanning line in parallel with the scanning line, and a portion arranged along a predetermined edge of the pixel electrode, wherein a width of the portion of the auxiliary capacitor electrode including the region overlapping the data line is larger than a width of the data line.