To efficiently purify a target position.SOLUTION: A purification method according to one embodiment includes the steps of: irradiating a measurement region with excitation light (S100)； detecting fluorescence from the measurement region (S102)； measuring an amount of amino acid in the measurement region on the basis of intensity of the fluorescence (S104)； and, when the amount of amino acid exceeds a first threshold (Yes at S106), discharging an agent toward the measurement region (S108).SELECTED DRAWING: Figure 12【課題】目的位置の浄化を効率良く行う。【解決手段】本開示の一態様に係る浄化方法は、測定領域に励起光を照射し（Ｓ１００）、測定領域からの蛍光を検出し（Ｓ１０２）、蛍光の強度に基づいて、測定領域に含まれるアミノ酸の量を測定し（Ｓ１０４）、アミノ酸の量が第１閾値を超えた場合に（Ｓ１０６でＹｅｓ）、測定領域に向けて薬剤を放出する（Ｓ１０８）。【選択図】図１２
