To provide a sterilization method of a sterilization filter in which a sterilization filter is sterilized by heated steam with a reduced thermal load to the sterilization filter as possible, so as to extend a durable period of the sterilization filter.SOLUTION: A sterilization method of a sterilization filter is configured to: supply heated steam to a sterilization filter that sterilizes supplied air； calculate an F value while measuring a temperature of the heated steam discharged from the sterilization filter by a prescribed time period ； and finish sterilizing the sterilization filter when the F value has reached a target value.SELECTED DRAWING: Figure 1【課題】除菌フィルタを加熱水蒸気により殺菌し、できる限り除菌フィルタに与える熱負荷を軽減して除菌フィルタの耐用期間を長くする除菌フィルタ殺菌方法の提供。【解決手段】供給されるエアを除菌する除菌フィルタに加熱水蒸気を供給し、除菌フィルタから排出される加熱水蒸気の温度を所定時間ごとに測定しつつＦ値を演算し、当該Ｆ値が目標値に達したときに除菌フィルタの殺菌を終了する除菌フィルタ殺菌方法。【選択図】図１
