The invention provides a liquid crystal display device for displaying an image, having a signal processing function and a narrow frame. In the display device of the invention, a signal processing circuit is formed by thin film elements and at least a portion of the signal processing circuit is formed in the region that extended the region where a wiring connection portion is formed along a side of a substrate. By providing the signal processing circuit outside the sealed region of liquid crystal and the like and utilizing regions beside an FPC connected portion which tended to be a dead space conventionally, a display device having a narrow frame can be provided.