An optical element is arranged in such a manner that a screen thereof can be hardly observed from a predetermined direction, and a deterioration of an image quality caused by moire does not occur. The optical element is constituted by a first polarizing layer, a second polarizing layer, and a liquid crystal layer arranged between these two polarizing layers. In the optical element, absorption axes of the first polarizing layer and the second polarizing layer are located parallel to each other; the liquid crystal layer is made of hybrid-aligned discotic liquid crystal; and an alignment axis of the liquid crystal layer is located parallel to, or perpendicular to both absorption axes of the first polarizing layer and of the second polarizing layer.