This paper deals with a method of finishing ceramics and metals to obtain a high degree of smoothness, and also deals with geometrical, crystallographic, magnetic, optical and chemical properties of finished surfaces. Float polishing is developed to polish many electronic and optical materials ultrafinely without deformed layers. Samples were mechanically polished on a tin lap having fine grooves of concentric circles while in a polishing fluid mixed with the pure water and fine powder. The samples were suspended in the polishing fluid by hydrodynamic phenomena due to the specially shaped tin lap. Very good flatness, excellent retention of edge geometry and extremely small surface roughness of 10ARz were obtained on the finished surfaces of amorphous materials and single crystals. The surface roughness of 20ÅRz were obtained on polycrystalline materials by float polishing using special techniques in order to reduce crystallographic anisotropy.