| 摘要 |
PROBLEM TO BE SOLVED: To provide a cleaning method with which removal efficiency can be improved for a foreign substance in a specific size.SOLUTION: A cleaning method includes a step for preparing a cleaning liquid (S10), and a step for cleaning an object to be cleaned by immersing the object to be cleaned in the cleaning liquid while irradiating the cleaning liquid with ultrasonic waves (S20). In the cleaning step (S20), in accordance with a size of a foreign substance to be removed with highest removal efficiency from the object to be cleaned, a concentration of nitrogen dissolved in the cleaning liquid is adjusted. Thus, a foreign substance in a specific size can be removed efficiently by changing the concentration of nitrogen dissolved in the cleaning liquid in accordance with a size of the foreign substance which is desired to be removed. |
