To realize a high-performance liquid crystal display device or light-emitting element using a plastic film. A CPU is formed over a first glass substrate and then, separated from the first substrate. A pixel portion having a light-emitting element is formed over a second glass substrate, and then, separated from the second substrate. The both are bonded to each other. Therefore, high integration can be achieved. Further, in this case, the separated layer including the CPU serves also as a sealing layer of the light-emitting element.