A light emitting unit for displaying light of different colors from two sides employs thin film filters of inorganic optical films. The inorganic optical film filters have the property of not absorbing moisture, thus do not damage light emitting elements. Moreover, the inorganic optical films do not absorb light, hence can fully filter the required light for use. The invention provides a technique that plates respectively a required inorganic optical film on the electrode or transparent substrate and a transparent package cap on two sides of an element. When light is generated from a light emitting element and passes through the color filters made of the inorganic optical films at two ends of the element, the inorganic optical films filter the light to become colored lights for displaying.