The present invention provides a light-emitting device whose volume is small and that has plural display screens, and a personal digital assistant that realizes higher added value by using the same. A light-emitting device of the present invention has a plurality of light-emitting elements in a pixel, and these light-emitting elements emit light in a different direction from each other and a pixel driving element is provided in one of the light-emitting elements. The light-emitting device can display in both front and back sides and independently display images on the both sides. Further, it can provide a higher aperture ratio, which is obtained by adding the aperture ratios of the both sides. Furthermore, it is also possible to see different images on the both sides of an electronic device using a display device of the present invention. Moreover, weight saving and thinning of electronic devices can be realized.