<p>Disclosed is a high-purity cerium polishing agent having a high cerium oxide content, which is improved in polishing rate. Specifically disclosed is a cerium polishing agent wherein the cerium oxide content relative to the total rare earth oxide (TREO) is not less than 90% by mass. This cerium polishing agent is characterized in that at least one specific element selected from the group consisting of Ti and group 5-12 elements having an atomic number of 80 or less is contained in an amount of 0.01-2.0% by mass relative to the total mass of the polishing agent.</p>
