To prevent clogging of a sanding roll having a grinding part electrodepositing diamond.

This sanding machine is constituted such that a metallic hair 34 of a dust removing brush 30 is brought into slide contact with the sanding roll 20 having the grinding part 21 constituted by electrodepositing diamond abrasive grains to remove grinding dust adhered on a surface of the sanding roll 20 so as to prevent clogging of the grinding part 21. Thereby, even when a lumber causing minute grinding dust is ground, grinding capability of the sanding roll 20 is maintained for a long time. Moreover, a high dust removing function is obtained for a long time by drawing the dust removing brush 30 near the sanding roll 20 in accordance with the wear of the metallic hair 34 of the dust removing brush 30.