A thin film transistor substrate for a display device includes a gate line; a gate insulating film disposed over the gate line; a data line disposed on the gate insulating film intersecting with the gate line to define a pixel area; a thin film transistor including a gate electrode connected to the gate line, a source electrode connected to the data line, a drain electrode, and a channel between the source electrode and the drain electrode; a protective film disposed covering the gate line, the data line, and the thin film transistor; a pixel electrode connected to the drain electrode of the thin film transistor; and a storage capacitor having a first upper storage electrode connected to the pixel electrode, and a second upper storage electrode connected to the first upper storage electrode on a side surface basis via a first contact hole passing through the protective film and the first upper storage electrode at an overlapping portion of the gate line and the first upper storage electrode.