Abstract: A grinder includes a rotatable disk to be pressed to a workpiece; a plurality of grinding bodies provided on one principal surface of the disk so as to cross a circumferential direction of the disk, each having a grinding stone chip on a side contacting the workpiece; and support devices, each supporting each of the grinding bodies so that the grinding stone chip swings with respect to the principal surface. Each support device supports each grinding body at a position at which an abrasion amount of the grinding stone chip is made uniform when the disk is rotated while being pressed to the workpiece so that a pressure to be applied to the grinding stone chip on an outer peripheral side of the disk becomes smaller than a pressure to be applied to the grinding stone chip on an inner peripheral side of the disk.