An organic electroluminescent device which has a low moisture permeability and an oxygen permeability. The organic electroluminescent device includes a substrate, an organic light-emitting unit having a sequentially stacked structure of a first electrode, an organic film, and a second electrode formed on a surface of the substrate, and an organic-inorganic composite film made of a dehydrated polycondensate of a hydrolyzed product of trialkoxy metal formed on an upper surface of the second electrode of the organic light-emitting unit. The organic-inorganic composite film simplifies a manufacture process and has high visible light transmittance. Therefore, the organic-inorganic composite film can be used as an intermediate layer of a front emission type organic electroluminescent device. Also, the organic-inorganic composite film has excellent prevention function of the entry of moisture and/or oxygen. Therefore, the encapsulation of the device is ensured even when a sealing substrate is not separately used, thereby decreasing the total thickness of the device and increasing the life span of the device.