A liquid crystal display device with low power consumption is provided. In the liquid crystal display device having a source signal line driver circuit, a gate signal line driver circuit, a DAC controller, and a pixel portion and performing an image display using an n-bit (n is a natural number, n≧2) digital image signal, one pixel has memory circuits for storing an n-bit digital image signal and a D/A converter, and the n-bit digital image signal for one frame can be stored in the pixel. In case of a static image display, the image signal stored in the memory circuits is read out every frame to perform the display, and thus, only a DAC controller is driven during the display. Therefore, this contributes to a reduction of the power consumption of the entire liquid crystal display device.