Provided is a method whereby a dairy product having a rich and creamy texture can be obtained by reducing or removing a reaction inhibitor of a protein deamidating enzyme contained in a raw material milk having low heat history to thereby more efficiently and more effectively treat the raw material milk having low heat history with a protein deamidating enzyme. A raw material milk having low heat history is treated with a protein deamidating enzyme after or simultaneously with a treatment, such as an addition of a calcium chelating agent, for reducing a protein deamidating enzyme inhibitor.