Although an organic resin substrate is highly effective at reducing the weight and improving the shock resistance of a display device, it is required to improve the moisture resistance of the organic resin substrate for the sake of maintaining the reliability of an EL element. Hard carbon films are formed to cover a surface of the organic resin substrate and outer surfaces of a sealing member. Typically, DLC (Diamond like Carbon) films are used as the carbon films. The DLC films have a construction where carbon atoms are bonded into an SP.sup.3 bond in terms of a short-distance order, although the films have an amorphous construction from a macroscopic viewpoint. The DLC films contain 95 to 70 atomic % carbon and 5 to 30 atomic % hydrogen, so that the DLC films are very hard and minute and have a superior gas barrier property and insulation performance.