From the point of view of Islam, the judge's duty is not only to resolve the enmity, but more importantly, to discover the truth; Because in judgment some many verses and narrations indicate the right verdict and the execution of justice. And this importance cannot be realized except by discovering the facts during the proceedings. The purpose of finding the facts is for the judge to reach the necessary knowledge and confidence in the diagnosis of the issue to issue a just verdict. But an important issue that can be raised is that, considering the existence of legal proofs in the Islamic legal system, how is the discovery of the fact realized? What is the guarantee of its implementation? And in this context, what is the difference between the Islamic legal system and the French legal system? These questions have been answered in this article.