This is a report on the renewal of the Transonic Flutter Testing Facility (Flutter Wind Tunnel) at NAL which was conducted between 1993FY - 1996FY. The report consists of three parts with a total of six chapters and four appendices. Part one consists of Chapters one to four, which provide an outline of the performance of the old as well as the new system. Chapter two provides an outline of the old system which was constructed in 1959. The concept design of the new system was produced by improving the basic design of the old system. Chapter three describes the purposes of the renewal, and the specifications and plans for the new system. The major aims were to reduce the turbulence the flow in the tunnel and to improve outdated hard ware. Specifications aimed to use the old wind tunnel structures and concept as much as possible. The proposed specifications are summarized. Chapter four describes the design of the new system performance. Performance and utility concerns are focus on the view point of clients. Part two corresponds to Chapter five, and describes the design concept and technical investigations concerning various issues in the renewal design, including the design of the pressure valve, high pressure tubes, chambers, test section and purge chamber. The design of these components takes into account not only aerodynamics but also structural dynamics factors. Part three consists of chapter six and four appendices and explains the measurement systems of the present facility. While the measurement system of the tunnel is beyond the scope of the renewal, it inevitably appears in this report. The four appendices are attached to aid understanding of the design routines of the present wind tunnel, and are entitled Appendix 1 'Numerical Wind Tunnel Model', Appendix two 'Pressure Losses in the High Pressure Tubes', Appendix three 'Method of Feedforward Control used in the new system', and Appendix four 'Calibration of Pressure'. As a result of the present studies, the renovation of the flutter testing facility was made possible by improvements in flow quality and renewal of hard ware bringing the new system up to a standard of performance as high as that of modern wind tunnels around the world. It is expected that this report will be of assistance to users and clients of the wind tunnel in the future.