A novel liquid crystal display device without a decrease in display quality. The liquid crystal display device includes a pixel for displaying a still image at a frame frequency of less than or equal to 1 Hz, and a liquid crystal layer in the pixel has a dielectric constant anisotropy of greater than or equal to 2 and less than or equal to 5. With the above structure, a change in voltage applied to a pixel can be kept within an acceptable range of a deviation in gray level for displaying the same still image. Thus, flickers due to a low refresh rate can be reduced, which leads to an increase in display quality.