An electroluminescent element which is superior in luminescence properties and lifetime can be provided by forming a thin film with high controllability according to the invention. An electroluminescent layer is formed over a first electrode by applying a current density of from 0.4 to 1.5 mA/cm2 for from 0.8 to 3.0 seconds to a first electrode of the electroluminescent element in accordance with the fact that an electrolytic polymerization film can be formed over the surface of the electrode uniformly by keeping a current density and time for applying the current to the electrode within a predetermined range during electrolytic polymerization especially when the electrolytic polymerization film is required to be a thin film.