It is an object to provide a driving method of a semiconductor display device by which generation of pseudo contour can be suppressed while suppressing the operating frequency of a driver circuit. It is also an object to provide a driving method of a semiconductor display device by which generation of pseudo contour can be suppressed while suppressing decrease in image quality. One mode of the invention is a driving method of a semiconductor display device, wherein a set of a plurality of subframe periods is provided in one frame period and the set of the plurality of subframe periods is inverted at some point to be provided.