A diffusing board which can suppress moire fringes, color flickering and screen brightness deterioration on a screen of a liquid crystal display device. On the surface of a transparent board (83), a pattern wherein substantially rectangular shapes are arranged in lattice by using a synthesized pattern (86) is formed. The synthesized pattern (86) is provided by synthesizing a plurality of first uneven patterns (84) having a linear shape which is long in one direction, and a plurality of concave lens shaped second uneven patterns (85) arranged at random.