To solve a problem of increased power consumption power due to wiring capacitances, which occurs when connecting onto a display substrate a substrate on which a memory, a memory controller, and the like are formed. The memory, the memory controller, and the like are integrally formed on the display substrate. At this time, these circuits are formed using a dual gate TFT. Thus, a display device in which wiring capacitances of connection portions between driver circuits composing a display and the memory controller and the like are reduced and which has thus low power consumption can be provided.