There is a problem in a dual emission device emitting light out of both surfaces that an image on the surface and an image on the rear surface are different from each other (either image is mirror-reversed). A dual emission device is disclosed in which either light emitted from the light-emitting device is reflected by glass including a semi-transmissive film to display on glass an image same as another image obtained also from the light-emitting device, and simultaneously, external information can be viewed through the glass. A mirror can be arranged between the dual emission device and the glass including a semitransparent film.