To prevent a polishing flaw from being generated in the end face of a book.

A polishing drum 5 is provided on a polishing stand 2. Two pieces of guide rails 12, 13 are provided on the polishing stand 2 and a book clamping mechanism 7 is moved along both guide rails 12, 13. The intersecting angle of the axial line L1 of the polishing drum 5 and the moving direction L2 of the book clamping mechanism 7 is regulated to an angle excepting 90 degrees e.g. to 85-87 degrees. Thereby, abrasive grains on sandpaper in the outer peripheral part of the polishing drum 5 are prevented from passing again, and again through the same positions of the end faces of books. Therefor, generation of a polishing flaw is prevented.