PROBLEM TO BE SOLVED: To provide an apparatus and method for sterilization washing process capable of obtaining high uniform sterilization effect in a short time.SOLUTION: In this apparatus, an ejector part 2 is provided to a strong acidic electrolytic water sucking route to suck the strong acidic electrolytic water stored in a tank 1 by a pump 3 and the sucked strong acidic electrolytic water is passed through the cavitation nozzle 10 provided on this side of a water discharge port to discharge the fine air bubble-containing strong acidic electrolytic water. The ejector part 2 is constituted so as to take in a gas containing chlorine gas naturally discharged into a gaseous phase from the strong acidic electrolytic water in the tank in order to mix the take-in gas containing chlorine gas with the strong acidic electrolytic water flowing toward the water discharge port. Then, the strong acidic electrolytic water, in which fine bubbles containing chlorine gas are dissolved, is discharged from the water discharge port.
