A method of highly purifying human serum albumin (HSA) which comprises bringing a fraction containing HSA produced by gene manipulation into contact with a chelate chromatography carrier having copper ions combined therewith and eluting the HSA adsorbed on the carrier by using a buffer having a pH of 5 to 7 and containing ammonium chloride as an antagonist. This method can provide a highly pure HSA free from yeast-origin components which have been dificult to remove satisfactorily by the conventional method of purifying HSA produced by gene manipulation.
