A decorative sheet in which the rainbow--colored interference fringes caused by irradiation with lights such as fluorescent lamp are not seen even if the mirror surface finish or the coloring layer of primary color is adapted, and in which the crack does not appear even if the decorative sheet concerned is applied to a curved surface, and a decorative board using thereof are provided. In the decorative sheet having a substrate, a coloring layer, an adhesive layer, and a transparent resin layer, an interference prevention layer is provided on a surface of the transparent resin layer, the surface being in opposite side to another surface being in contact with the adhesive layer.