A light-emitting element layer and an element layer, which includes an anode and a cathode that sandwich the light-emitting element layer, are formed, and a sealing film is formed so as to cover the entire element layer. In the step of forming the sealing film, a first inorganic film is formed on the element layer. An organic film is formed on the first inorganic film. The organic film is ashed by using a foreign substance remaining on the organic film as a mask such that the organic film is left at least immediately below the mask and removed from at least a part of other areas. After the organic film is ashed, a second inorganic film is formed at least on the first inorganic film.