Baitul Maal wat Tamwil (BMT) is one of the Islamic Microfinance Institutions which is under supervision of Financial Service Authority (FSA). This research aims at studying the role of the Financial Services Authority (FSA) in supervising BMT and also the efforts of the FSA to protect the customers of BMT. In this research the author uses the normative legal research method which used the literature study to find the material or data related to the issue. Data therefore collected from reading journals, books, laws or regulations related to the research issue. Primary legal material consists of several laws, regulation, Government Regulation, policies, such as laws related to the Financial Service Authority, microfinance institution, especially for the Islamic Microfinance Institution. This research found that Financial Services Authority (FSA) has the authority to supervise microfinance institutions such as Baitul Maal wat Tamwil (BMT) implemented in different ways, settings, control and guidance of the Microfinance Institution. FSA also make some rules governing consumer protection or the protection of people who use services of microfinance institution. The form of legal protection of BMT consumer is divided into preventive protection and repressive protection. The community has opportunity to raise objection or opinions before the government’s decision received a definitive form. The law should protect the consumer as the subjective conditions that must be created to keep the consumers.