Provided is a molecular electronic device including an electrode including a conductive polymer electrode layer. The molecular electronic device includes a first electrode; a functional molecular active layer, self-assembled on the first electrode, including an electroactive functional group having a cyclic compound; and a second electrode disposed on the functional molecular active layer. The second electrode includes a conductive polymer electrode layer contacting with the functional molecular active layer and a metal electrode layer disposed on the conductive polymer electrode layer. The conductive polymer electrode layer of the second electrode prevents damage to the functional molecular active layer, thereby preventing a short circuit in an ultra-thin molecular electronic device.