To provide a method for washing/sterilizing a milking parlor which is based on a new washing method using no dairy detergent, exerts no bad influence on the human body and environment, lowers a load on waste water treatment or the like and exhibits satisfactory washing/sterilizing effects and to provide an apparatus therefor.

A circulating means is arranged for circulating tepid water, inorganic alkaline agent-added strong alkaline electrolytic water and strong acid electrolytic water (obtained by adding an inorganic acid agent such as hydrochloric acid) successively through a milk sending route including a milk sending pipe 21'.