臺灣近年受到嚴重的細懸浮微粒污染，對人民而言，此一名詞也是從陌生到熟悉，然不但政府部門多未在法體系中做相應的因應，而未有具體的法律管制，法學界對於此一問題目前也鮮少討論。本文的目的在於探討臺灣面對細懸浮微粒的問題目前在管制上有何不足？以何等管制工具進行管制較為適當？透過本文採用文獻分析及制度分析的研究方法，認為目前的管制機制無法適切回應此等風險問題的特性，在管制上存在著難以事後究責、傳統管制工具缺席、中央政府過度主導、地方本位及無法解決跨境污染等困境。故在政策上應適度的運用預防原則，朝地方分權、擴大產品製程中行為者事前責任，落實資訊的蒐集與公開，改革既有空氣污染防制法中命令控制式管制機制，並將細懸浮微粒納入管制，善用協商及經濟誘因的管制工具進行管制，才能確實解決問題。

Taiwan has been polluted by Particulate Matter (PM2.5) in recent years. The norm of "PM2.5" has been from strange to be familiar with for Taiwanese people. Although this issue has many legal argument in environmental law, but the law scholars have few discussions. Of course, the regulation tools about PM2.5 are discussed less and less. This article aims to explore the lack of PM2.5 regulation in legal system. What regulation tools are appropriate to regulate humans' actions? This article adopts documentary analysis and institution analysis as research methods, and finds the problem of PM2.5 is one kind of risk. Also, this article finds the current regulation tools cannot respond to the characteristic of this kind of risk. The current legal system has many problems resulting from regulation failure, including no accountability, absence of traditional regulation tools, over-leading of central government, and the local egoism unable to deal with cross-border pollution well. Therefore, we need to use preventive measures appropriately, forward decentralization, expand product liability, and implement information collection and disclosure. Besides, we should reform command and control system in Air Pollution Control Act, use negotiation and economic incentive as regulation tools. This article concludes if we can regulate PM2.5 by following these directions in environmental policies, then we can let the laws handle PM2.5 well.