Cleaning method and cleaning apparatus

A cleaning apparatus, comprising:

• a nozzle configured to eject a jet of a cleaning liquid;
• a moving device configured to relatively move the nozzle to a plurality of target portions of a workpiece;
• a positive displacement pump connected to the nozzle, the positive displacement pump configured to change a rotation speed;
• a pressure gauge configured to measure an ejection pressure of the positive displacement pump;
• a control device including
• a storage device configured to store
• a numerical control program,
• a first pressure,
• a second pressure lower than the first pressure, the second pressure being the ejection pressure configured to increase to the first pressure within a predetermined period during which the nozzle moves between the two of the target portions among the plurality of the target portions, and
• a first range,
• a numerical control unit configured to control the moving device based on the numerical control program,
• a pressurizing unit configured to set a target pressure to the first pressure when a remaining moving amount to a target position that is acquired based on a current position is within the first range, and configured to set the target pressure to the second pressure otherwise, and
• a feedback control unit configured to perform a feedback control of the rotation speed so that the difference between an ejection pressure of the nozzle and the target pressure becomes zero.