A method of manufacturing a reflective mask blank comprising a multilayer reflective film formed on a substrate so as to reflect EUV light; and a laminated film formed on the multilayer reflective film. The method includes the steps of depositing the multilayer reflective film on the substrate to form a multilayer reflective film formed substrate; carrying out defect inspection for the multilayer reflective film formed substrate; depositing the laminated film on the multilayer reflective film of the multilayer reflective film formed substrate; forming a fiducial mark for an upper portion of the laminated film to thereby form a reflective mask blank comprising the fiducial mark, the fiducial mark serving as a reference for a defect position in defect information; and carrying out defect inspection of the reflective mask blank by using the fiducial mark as a reference.