A polishing composition used in wafer polishing process for eliminating protrusion around laser mark, thereby achieving a flat polished surface, as well as a wafer polishing method using the polishing composition. A post-polishing composition for elimination of a laser mark remaining after polishing of silicon wafer with a primary polishing composition containing silica particles, water, and a basic compound, the post-polishing composition including silica particles, water, a tetraalkylammonium ion, and a water-soluble polymer, wherein the mass ratio of the tetraalkylammonium ion to SiO2 of the silica particles is 0.200 to 1.000:1; the mass ratio of SiO2 dissolved in the polishing composition to SiO2 of the silica particles is 0.100 to 1.500:1; and the mass ratio of the water-soluble polymer to SiO2 of the silica particles is 0.005 to 0.05:1. The silica particles have an average primary particle diameter of 1 nm to 100 nm.