A mother substrate for a display device includes: a first mother substrate and a second mother substrate including a plurality of panel regions and facing each other; a first contact electrode and a second contact electrode on the first mother substrate; a common electrode, a first voltage application electrode and a second voltage application electrode separated from each other and on the second mother substrate; and a liquid crystal layer between the first mother substrate and the second mother substrate. The first voltage application electrode is connected to the first contact electrode, and the second voltage application electrode is connected to the second contact electrode. The first voltage application electrode is applied with a first voltage, and the second voltage application electrode is applied with a second voltage different from the first voltage.