In order to provide a display device of high reliability in which an amount of moisture and oxygen, which are a factor for deteriorating a characteristics of a display device, entering from a sealing agent is reduced and its manufacturing method, the present invention has a sealing film. Accordingly, an interlayer insulating film including an organic material of the display device (panel) is no longer exposed to the atmosphere outside of the display device. Therefore, it becomes possible to prevent moisture and oxygen outside of the display device from entering inside of the display device through an insulating film and the like including a hygroscopic organic material. In addition, various degradations such as contamination of an inner part of the display device caused by moisture, oxygen and the like, the degradation of electric properties, a dark spot and shrink can be prevented, thus enhancing reliability of the display device.