The invention decreases the power consumption in an EL display and illumination device that each use EL elements. In an EL display or EL illumination device that use EL elements, the magnitude of the voltage or current that is applied to the EL elements during driving is set to a voltage value or current value (V1 to V2) at which the luminous efficiency of the EL elements is 80% or more (0.8P to P) of the maximum P.