Ultrasonic cleaning device

An ultrasonic cleaning method using an ultrasonic cleaning device, comprising the steps of:

• immersing a slide surface of an ultrasonic propagation tube in a liquid film of a cleaning liquid formed on a cleaning surface of an object to be cleaned;
• propagating ultrasonic wave inside said ultrasonic propagation tube by repeating reflection of the ultrasonic wave provided by an ultrasonic transducer to the cleaning liquid that flows through said ultrasonic propagation tube;
• transmitting a part of the ultrasonic wave through said ultrasonic propagation tube, propagating in the liquid film of the cleaning liquid and reaching the object to be cleaned;
• and cleaning the cleaning surface of the object to be cleaned by the ultrasonic wave and the cleaning liquid,
• wherein said ultrasonic cleaning device comprises said ultrasonic transducer for providing ultrasonic energy to the cleaning liquid;
• said ultrasonic propagation tube for flowing the cleaning liquid provided with the ultrasonic energy by said ultrasonic transducer;
• a holding mechanism disposed below said ultrasonic propagation tube for holding the object to be cleaned;
• and an outlet provided on said ultrasonic propagation tube for discharging said cleaning liquid to the cleaning surface of the object to be cleaned held by said holding mechanism,
• and wherein said outlet is a slit or a plurality of holes provided on a side wall of said ultrasonic propagation tube.