In a multi-window display device, the following has been merely performed: before data for plural screens is inputted to a display, video signals themselves are subjected to signal processing, and the processed video signals are inputted to the display, whereby display is performed. Therefore, a circuit for performing signal processing, for example, an IC has a complicated structure since video signals for plural screens are stored in a memory. There is provided a pixel structure in which: signal lines for plural screens are arranged; and one of the signal lines is selected to supply a video signal to a display element. For example, in the case of performing display of two screens, there is provided a pixel structure in which: two signal lines, which are inputted with respective video signals for a first screen and a second screen, are arranged; and one of the signal lines is selected to supply a video signal from the selected signal line to a display element.