Judge d’instruction, is a French legal term used to describe the role of investigating magistrate (judge of inquiry). Judge d’instruction is responsible for performing an investigative role in a criminal trial which evidence is gathered, witnesses are heard and depositions are taken by a judge rather than public persecutor. This concept was developed by French judicial system in the 17th century, and it is different from the grand jury hearing in the Anglo-American system. This research discusses the role of the Judge d’instruction from a comparative point of view, and provides a legal discussion among scholars on the application of this concept in UAE legal system.