A flexible EL device comprises a substrate, which is made of highly polymerized synthetic rubber, polyurethane, or silicon rubber, a conductive layer, a dielectric layer, a fluorescent layer, a transparent conductive layer, and a polymer protection film layer. Due to the high flexibility of the substrate, the flexibility of the flexible EL device according to the present invention is higher than the conventional EL device using PET, and therefore, the durability of the flexible EL device under mechanical impact is improved. As a result, the flexible EL device is not damaged when physical impacts are applied to the flexible EL device. Furthermore, noise is prevented or reduced by simply changing the structure of the flexible EL device and adding material layers, and therefore, electric and physical properties of the flexible EL device are improved. The flexible EL device is applicable to EL dome sheets or EL keypads.