In a program, threading problems are very hard to detect and locate since they are usually considered 'errors' in the program logic. The reason for this is that threading problems are often non-deterministic problems such as race conditions and deadlock. These kinds of problems do not happen in every run of the program and even they happen, the program runs as usual but generates wrong outputs. The Threading Debugger inside Intel Inspector works as an efficient diagnosis tool against threading errors in the program even if the program does not encounter the error. This debugger is especially particularly helpful when building HPC applications and optimizing codes using multi-threading algorithms.