The present invention provides a transparent screen which is excellent in transparency and in which a reflection part contour at the time of not displaying an image is unlikely to be recognized. An optical sheet of the present invention includes a substrate; and a cholesteric liquid crystal layer on the substrate, in which the entire cholesteric liquid crystal layer is surrounded by an imaginary contour line, the cholesteric liquid crystal layer has a uniform region and a modulation region that is located between the uniform region and at least a part of the imaginary contour line, a shortest distance between the imaginary contour line and the uniform region is 10 mm or longer, and a reflectance of the modulation region monotonously decreases from the uniform region side toward the imaginary contour line side.