To securely remove minute foreign matters remained in manufacture of parts for a bearing.

A process 4 for removing the minute foreign matters remained is provided before a precision water cleaning process 5 to remove the foreign matters remained, such as metal powder of materials and damaged and dropped pieces of components for bearing parts, produced during a cutting process 1, a heat treatment process 2 and a grinding process 3 in manufacturing processes of each component parts for a rolling bearing. In the process 4 for removing the minute foreign matters remained, damage to surfaces of parts for the rolling bearing which are caused by removing operations of such foreign matters remained can be restrained to a lower level by using crashed materials made of raw materials of an ear core of maize as grinding media. Such media is easily adaptable to the surfaces of the parts for the bearing and the minute foreign matters can be effectively removed.