The treatment of ozone water cleaning after the machining in an ethanol environment is to be used to fabricate aluminum vacuum chambers of the Taiwan Photon Source. Aluminum samples followed the ozone water cleaning process were analyzed by the techniques of thermal outgassing rate measurement, photon- stimulated desorption (PSD) rate measurement and the Auger electron spectroscopy analysis. The result showed that the ozone water cleaning process has a superior performance. A thermal outgassing rate of ~6.4 × 10-12 Pa m /s at 72 hours after the pumping from one atmosphere and a PSD rate of ΔP/I ~ 9.3 × 10-11 mbar/mA at an accumulated beam dose of 1 A h were obtained.