Abstract: An air-flushing device cleans a cleaning object by air-blowing to the object from a nozzle. The air-flushing device outputs a pressure value changing according to electromagnetic valve's opening/closing, and controls the valve's opening/closing based on two reference values of an upper-limit setting value and a lower-limit setting value lower than that. The air-flushing device closes the valve if the pressure value changes from lower than the upper-limit setting value to that or higher, and opens the valve if the pressure value changes from higher than the lower-limit setting value to that or lower.