Ultrasonic cleaning method

An ultrasonic cleaning method for cleaning a front surface of a cleaning target. the acoustic cleaning method comprising:

• a preparation step, preparing an acoustic cleaning apparatus comprising:
• a cleaning stage, holding the cleaning target on a holding surface;
• and an acoustic head provided to be spaced apart from the cleaning stage and having:
• a plurality of ultrasonic wave generators being directional;
• and a casing to which the ultrasonic wave generators are installed, so that a plurality of ultrasonic waves generated from the acoustic generators are concentrated;
• a cleaning liquid coating step, coating a cleaning liquid on the front surface of the cleaning target held on the cleaning stage;
• a peeling step. after the cleaning liquid coating step, irradiating the front surface of the cleaning target coated with the cleaning liquid with the ultrasonic waves generated from the ultrasonic generators installed to the acoustic head, and peeling off a foreign matter attached to the front surface from the front surface;
• and
• an attracting step, concentrating the ultrasonic waves generated from the ultrasonic wave generators installed to the acoustic head at a gap between the casing and the holding surface of the cleaning stage to form a low pressure region whose pressure is lower than atmospheric pressure at the gap, and attracting the foreign matter peeled off from the front surface of the cleaning target and the cleaning liquid coated on the front surface to the low pressure region.