A structure of a display device in which water is prevented from passing through the side faces of a display device using an organic light-emitting element and a gap between substrates is made uniform. On the first substrate having the light-emitting element provided thereon, the thicknesses of the layers deposited in the peripheral area, the pixel portion and the driving circuit portion are equalized with each other. Furthermore, an adhesive is provided as thin as possible in the peripheral area of the first substrate so as to bond a second substrate to the first substrate. As a result, the distance between the first substrate and the second substrate can be made uniform throughout the peripheral area of the first substrate, the pixel portion and the driving circuit. Moreover, since a protective film overlying the organic light-emitting element is also provided on the side faces of the second insulating film, water is prevented from entering the display device through its side faces.