An organic electroluminescent device includes a substrate, an organic electroluminescent portion, and a packaging plate. The organic electroluminescent portion is formed on the substrate, and the packaging plate is joined with the substrate to cover the organic electroluminescent portion. A sealant is disposed between the substrate and the packaging plate to join the substrate with the packaging plate. The organic electroluminescent device may include a diffusion preventing portion disposed on at least one of the packaging plate and the substrate to prevent the sealant from contacting the organic electroluminescent portion. The organic electroluminescent may include a moisture absorbent film disposed on at least one of the substrate, the packaging plate, and the organic electroluminescent layer.