A circuit array substrate includes an optically transparent substrate, pixels having switching elements formed on the transparent substrate, gate electrode lines connected to the switching elements, the gate electrode lines being provided on a first insulation film with separating portions in the pixels, signal lines connected to the switching elements, the signal lines being provided on a second insulation film which is different from the first insulation film, and electrically conductive portions provided on the second film to electrically connect the electrode lines with the separating portions to each other. The separating portions reduce electrostatic capacitances defined between the gate electrode lines and the switching elements when the conductive portions are not connected between the separating portions.