To provide a method for forming sterile or substantially sterile concentrated milk liquid such as milk without carrying out any significant heat treatment.

This method includes the formation of milk concentrate by concentrating starting milk from a concentration of about 2 to one of about 7 by using an ultrafiltration membrane. Afterwards, the milk concentrate is filtered by using a microfilter so that sterile or substantially sterile concentrated milk can be provided. As for the obtained concentrated milk, all bacteria is about 0.5 percent or less, and colony forming unit of spore forming bacteria per gram is less than about 5. Substantially, the sterile concentrated milk undergoes no significant heat treatment during working.