A sealing structure is provided without irradiating a pixel portion of a light emitting element by heat or UV light. By the sealing structure, the reliability is enhanced by blocking out oxygen and moisture, and preventing the deterioration of the light emitting element. The sealing structure in which a whole surface of the pixel portion is covered with a sealing material and which has an excellent sealing property is manufactured without being exposed to heat or UV light. In this case, a catalyst for curing a sealing material is formed as a film on a substrate, and a sealing material for covering a pixel portion is applied to the other substrate. Then, the both substrates are bonded together.