The concept of the highest-grade mirrors with optical polishing methods—namely, super-smooth mirror-like surface—has been defined. Such surfaces may have a wavelike profile formed with regularly arranged atoms such as AFM (atomic force microscopy) or STM (scanning tunneling microscope) images of a silicon cleavage face. If high-density atoms are arranged, the peak and valley of the surface roughness will be one-tenth or one-hundredth of the atomic diameter. Although the surface roughness is different depending on the work materials, the peak and valley of the surface roughness on a super-smooth mirror surface is expected to be small.