To polish the glass surface with a high accuracy by polishing the glass surface with a polishing liquid at a pH previously approximated to that of glass.

A polishing agent such as red iron oxide, cerium oxide, titanium oxide or colloidal silica having 0.2-30 μm, preferably 0.2-20 μm, especially preferably 0.2-12 μm particle size distribution in an amount of 1-20 wt.% is dispersed in water or a mixed solvent of water with a water-soluble organic solvent to provide a polishing liquid. A glass composed of a phosphate glass or fluorophosphate glass of the same kind as that of a glass to be polished is then dipped in the polishing liquid to elute the glass component into the polishing liquid and regulate the pH thereof within ±1.0, preferably within ±0.7, especially preferably within ±0.5 based on the pH of the glass. The resultant polishing liquid is used to polish the phosphate glass or fluorophosphate glass and afford a glass product having ≤7 μm width of linear flaws on the surface. Thereby, the occurrence of latent flaws, etc., can be reduced.