In order to enhance the reliability of software, programmers have first to detect program errors and then to remove them. Although many errors can be detected during compilation when high level programming languages are used, still the degree of detection achievable by a compiler will be limited to the static aspect of program errors. Therefore, we need further investigation into a more sophisticated programming and debugging environment. This paper presents an environment which involves a debugging tool to help us detect logic errors and remove them efficiently. The debugging tool is supported by a special architecture named SPRING which was originally developed for reliable execution of Ada or Pascal programs. Following an overview of the system backed up by SPRING, the details of SPRING architecture are described, and the implementation of high level debugging on the SPRING architecture is discussed. In conclusion, our trial could be seen as a step toward providing an advanced programming environment for the development of reliable software.