A reflective mask blank, a reflective mask, and methods for manufacturing those, which suppress reflectance at a light-shielding frame. The reflective mask includes a substrate, a multilayered reflective layer formed on the substrate, an absorption layer formed on the multilayered reflective layer, and a frame-shaped light-shielding frame area at which the absorption layer has a film thickness larger than a film thickness at other areas. The multilayered reflective layer is diffused and mixed at the light-shielding frame area through melting.