Patent ID: 8652227

Claim:
A method for polishing comprising the step of ejecting an abrasive cleaning agent comprising: an elastic material which includes a soluble nitrogen substance as a primary component, obtained from tubers of devil's tongue starch and containing mannan as primary component, and whose water content is 10% to 30%; and abrasive grains having an average grain diameter of 53 μm or less, which are provided in an amount of 1 to 30 percent by weight, with respect to the elastic material, and which are supported on surfaces of the elastic material and/or are buried in the elastic material, wherein; a grain diameter of the abrasive cleaning agent is from 88 to 1190 μm; onto a workpiece at an acute incident angle using a dry ejecting method with an ejection velocity of 30 m/s or more or an ejection pressure of 0.05 MPa or more.