Provided is a transistor. The transistor includes: a substrate; a semiconductor layer provided on the substrate and having one side vertical to the substrate and the other side facing the one side; a first electrode extending along the substrate and contacting the one side of the semiconductor layer; a second electrode extending along the substrate and contacting the other side of the semiconductor layer; a conductive wire disposed on the first electrode and spaced from the second electrode; a gate electrode provided on the semiconductor layer; and a gate insulating layer disposed between the semiconductor layer and the gate electrode, wherein the semiconductor layer, the first electrode, and the second electrode have a coplanar.