An optical element having a plate-like shape includes a light-transmitting resin and minute regions. The minute regions are dispersedly distributed in the light-transmitting resin and have a birefringence different from the light-transmitting resin. At least one of the light-transmitting resin and the minute regions contains at least one luminescent material. The thus arranged optical element omits the necessity to separately provide a light emitting means made of a light-transmitting resin containing reflective dots or the like as in a conventional manner, while being capable of allowing light, which results from excitation by incident light in the optical element (through the luminescent material), to be emitted to the outside in the form of linearly polarized light having a certain plane of vibration.