The purpose of this research is to find out whether the pretrial institution has realized the due process of law as aspired by the criminal procedural law and what about the pretrial reform institution in the RKUHAP, namely the Preliminary Examination Judge, whether it has been able to reflect the due process of law. The type of research in this study is normative. The data source used is secondary data which contains primary, secondary and tertiary legal materials. The data was collected by using library techniques and analyzed by qualitative methods and will be described systematically or prescriptively. From the Research It was found that the current pretrial does not reflect the due process of law, so it is necessary to immediately approve the reform of the pre-trial institution. Then the pretrial substitute institution, namely the Preliminary Examination Judge has greater authority than pretrial regarding the rights of the suspect, so that the establishment of this pretrial substitute institution is expected to have the purpose of criminal procedural law: due process of law or behoorlijk procesrecht in order to seek material truth or objective truth and the purpose to protecting the human rights of suspects and defendants can be achieved.