It is an object to propose a display device in which reflection of external light on a reflective polarizing plate is prevented and also extraction efficiency of light from a light-emitting layer is improved. If the display device has a light-emitting layer provided over a reflective electrode, a transparent electrode provided over the light-emitting layer, a transparent substrate provided over the transparent electrode, a reflective polarizing plate provided over the transparent substrate, a quarter wave plate provided over the reflective polarizing plate, and a polarizing plate provided over the quarter wave plate, reflection of an outside image can be suppressed, and light emitted in the light-emitting layer can be extracted efficiently.