The present invention realizes a display device with dummy pixel portions and a frame region required for the dummy pixel portions and code notation, in which the frame region is minimized while achieving code notation in required size.In the dummy pixel portions, the number of gate electrodes in a thin film transistor formed by a semiconductor layer is reduced to two, so that distances from a contact hole to another contact hole and to a through-hole can be shortened as compared to those in pixel formation portions, allowing placement of the contact hole and the through-hole in a lower portion in the figure. Provided in the vicinity of the center of the dummy pixel portion is only an electrode equivalent to a storage capacitance line. Thus, a wide transparent region can be ensured to note a code of a sufficient size in the dummy pixel portion.