A method for easily and efficiently separating a sialyllactose material from a milk material is disclosed. The method comprises removing proteins from the milk material to obtain a protein-free liquid, adjusting the pH of the protein-free liquid to obtain a pH-adjusted liquid, and concentrating the pH-adjusted liquid by an ultrafiltration (UF) membrane. Since the method also allows separation of sialyllactose from lactose and minerals, sialyllactose can be obtained with high purity, making the sialyllactose material highly useful for food, pharmaceutical, and other applications.