Non-Destructive Defect Inspection is one of the urgent requirements to effectively detect internal defects of aged structures. Especially for countries like Japan or USA, many old structures such as tunnels, buildings and roads exist. Several methods of Non-Destructive Defect Inspection Equipment are in place today. We offer a newly developed Non-Destructive Defect Inspection method utilizing UWB radar based architecture. Our Non-Destructive Defect Inspection method employs patented UWB ultra high sensitivity receiving system and synthetic aperture radar architecture. By employing the above two technologies, we could design high speed and high-resolution Non-Destructive Defect Inspection Equipment.