A liquid crystal element includes a transparent substrate and a liquid crystal layer which is composed of a liquid crystal material and includes a concavo-convex portion having a periodic undulation. The concavo-convex portion of the liquid crystal layer is located in a transparent substrate side and the direction of the major axis of liquid crystal molecules located in an undulation surface thatis an interface of the concavo-convex portion of the liquid crystal layer is aligned in substantially vertical direction to the undulation surface in the transparent substrate side, or the concavo-convex portion of the liquid crystal layer is located in a medium side opposite to the transparent substrate and the direction of the major axis of liquid crystal molecules located in the undulation surface that is the interface of the concavo-convex portion of the liquid crystal layer is aligned in substantially vertical direction to the undulation surface in the medium side. Accordingly, the liquid crystal element forms a diffractive grating.