The method of the present invention cleans abrasive faces of an upper abrasive plate and a lower abrasive plate of an abrasive machine. The method is executed by a cleaning device including: a nozzle for jetting water; a brush for preventing the jetted water from scattering in the air, the brush enclosing the nozzle; and another brush for closing a gap between the preventing brush and an outer edge of the upper abrasive plate, the method is characterized by the steps of: jetting water from the nozzle toward the abrasive face of the upper abrasive plate; moving the nozzle toward the outer edge of the upper abrasive plate; and closing the gap by the closing brush when the gap is formed between the preventing brush and the outer edge of the upper abrasive plate.