There is provided a light diffusing member for a transmission screen that has a satisfactory surface protective effect while maintaining excellent light diffusing effect and antireflective effect. The light diffusing member for a transmission screen comprises a hard coat layer provided on a surface of a substrate having a single-layer or multilayer structure, wherein fine particles are contained in the substrate and the hard coat layer, and the average particle diameter of the fine particles contained in the hard coat layer is 5 to 15 .mu.m, the hard coat layer has a thickness satisfying a requirement represented by formula (d-2).ltoreq.t.ltoreq.d wherein t represents the thickness of the hard coat layer, .mu.m; and d represents the average particle diameter of the fine particles, .mu.m, and a part of the fine particles is projected on the surface of the hard coat layer to constitute concaves and convexes.