PURPOSE: To obtain a high-purity coenzyme Q in high yield industrially advantageously, by purifying crude coenzyme Q by silica gel chromatography using a developing agent consisting of a mixture of an aliphatic ketone and a nonpolar solvent.

CONSTITUTION: Silica gel is fed to a column using a mixture of 10W50vol% aliphatic ketone (e.g., acetone, methyl ethyl ketone etc.) and a nonpolar solvent (e.g., n-hexane, n-pentane, etc.), and it is replaced by a mixture of an aliphatic kethone having an aliphtic ketone content not less than 0.2vol% in a volume not more than that used in development and a nonpolar solvent. The silica gel is charged with crude coenzyme Q dissolved in a developing solvent cosisting of 0.3W20vol% aliphatic ketone and a nonpolar solvent and the developing solvent is made to flow continuously so that coenzyme Q is eluted.