公共設施的設立雖被視為公共利益的增進，但我國公共設施閒置的現象卻也十分普遍，因而引發許多關注、爭議與批評，使閒置公共設施活化的議題，成為近年行政管理的重要目標。對此，本文的研究目標有二:首先透過政策終結的理論觀點，探討我國閒置公共設施進行活化的決定因素；其次，在確保活化目標的基礎上，更進一步探討活化過程的課責機制，以行政、法律、政治、專業等四種面向進行分析。試圖對未來的活化策略以及課責機制的精進，提供實務上之政策建議。 依據上述目標，本研究以行政院公共工程委員會104年第三季的113個列管案件為分析對象，透過系統性的文獻分析與整理，以及利害關係人的深度訪談進行實證研究。由研究結果可知，法律障礙、經濟成本與心理抗拒等三項因素，是誘發我國閒置公共設施選擇進行全面活化的主要因素；而若從活化執行過程的課責機制面向來看，行政課責與政治課責是亟待改進之處。 最後，依據研究成果，本文提出之研究建議包含：（一）強化機關的政策評估能力：在公共建設計畫的編審作業階段嚴格要求成本效益分析、環境影響評估的執行，以強化計畫與人民需求之間的連結；（二）納入公民參與機制：透過公聽會、座談會的舉行，瞭解人民需求，確保政府決策的公開透明，並強化政府與人民間的信任關係；（三）建立適當的退場機制：針對區位不佳或活化成本過高的列管案件，給予適度的法規鬆綁，以避免閒置公共設施的再次閒置。 / Although public facilities are built to promote public interest, idle public facilities are everywhere in Taiwan. This so-called “mosquito houses” phenomena have gotten public attention to cast doubts on government effectiveness. In response, government activates a new program to reinventing idle public facilities. This research is design to explore the factors through which government implements the reinventing program. Under the guidance of policy termination and accountability theories, this study explores the mechanism of accountability behind the reinventing program in four dimensions, included political accountability, bureaucratic accountability, legal accountability and professional accountability. This research is expected to provide theoretical answers and practical suggestion to enhance the reinventing program as well as the mechanism of accountability behind public facilities construction decisions. This research utilizes government documents to analyze 113 “mosquito house” cases monitored by Public Construction Commission, Executive Yuan as well as literature review and in-depth interviews. The results indicate that, the legal obstacles, economic costs and the psychological reluctance, were the decisive factors to lead to the activation of reinventing program. As for the accountability, it would be urgent to improve the mechanism of administrative accountability and political accountability. Lastly, this study could provide three main practical suggestions as follows: (1) Strengthening the capacity of policy assessment in government, (2) bringing in the citizen participation (3) Building a mechanism of public facility termination.