The present invention has an object of providing a light-emitting device including an OLED formed on a plastic substrate, which prevents degradation due to penetration of moisture or oxygen. On a plastic substrate, a plurality of films for preventing oxygen or moisture from penetrating into an organic light-emitting layer in the OLED (“barrier films”) and a film having a smaller stress than the barrier films (“stress relaxing film”), the film being interposed between the barrier films, are provided. Owing to a laminate structure, if a crack occurs in one of the barrier films, the other barrier film(s) can prevent moisture or oxygen from penetrating into the organic light emitting layer. The stress relaxing film, which has a smaller stress than the barrier films, is interposed between the barrier films, making it possible to reduce stress of the entire sealing film. Therefore, a crack due to stress hardly occurs.