In laser purification of Ag from an Ag-In alloy based on multistep photoexcitation for ionization, we demonstrated that a time-division collection method employing a high-speed rotation disk is effective in suppressing an impurity level. High purity Ag film of 0.11&percent; In impurity concentration was obtained from a starting Ag-In alloy of 6.08&percent; In. This impurity reduction was much higher than the case without the new method, in which only half reduction was obtained. This work also showed that the contamination is mainly due to neutral atoms that failed to be irradiated by pulsed-mode lasers. ©1998 American Institute of Physics.