The general milestones of the Institute of National Remembrance (IPN) Archives activity were - except for the very forming of the Institute - the most important stages of its functioning (in material and formal way). The archival resources of the former Commission for the Prosecution of the Crimes against Polish Nation, containing the most important records concerning mainly the German occupation of Poland (1939-1945) and partially the events of the Soviet occupation (1939-1941) and the crimes of the Communist dictatorship in the years 1944-1956 (so called "Stalinist crimes") as well as the records of the investigations concerning those periods, formed the very first part of the archival resource of the IPN. Simultaneously the transfer of the records of former Communist security apparatus branches from the archives of the Ministry of Internal Affairs and Administration, the Office of the State Protection (Urząd Ochrony Państwa, UOP) and after its split from its successor agencies, i.e. Homeland Security Agency (Agencja Bezpieczeństwa Wewnętrznego, ABW) and Intelligence Agency (Agencja Wywiadu, AW), the Military Intelligence Service (Wojskowe Służby Informacyjne), and after its liquidation from its successor agencies, i.e. Military Counterintelligence Service (Służba Kontrwywiadu Wojskowego, SKW) and Military Intelligence Service (Służba Wywiadu Wojskowego, SWW), the Border Guard (Straż Graniczna, SG) started and formed the torso of the IPN archival resource. The acquired records of the former Communist security police as well as military security organisations and counterinsurgency troops and the judicial bodies were the most important assets for the fullfilment of the IPN's legal tasks and research activities. From 1999 on, the IPN Archives are still gathering the records concerning the recent Polish history from the various state institutions, archives and private individuals.

The acquisition process and description of the previously secret archival records of the Communist security and oppressive bodies progressed simultaneously to the rise of the public interest in the access to those records - and to the significantly broadened range of the lustration of the public personalities. The changes in lustration laws introduced in 2006, and transfer of the lustration tasks from the Bureau of the Public Interest Authority (Biuro Rzecznika Interesu Publicznego, BRIP) to the IPN contributed to the significant rise of the IPN Archives duties and efforts.

The subsequent changes in the legislation concerning IPN and its public duties contributed also i.a. to the liberalisation of the legal approach towards access to the records for the parties affected or interested and the obligation to publish a detailed inventory of records (called Inwentarz Archiwalny - the Archival Inventory, accessible online and constantly complemented) (by the amendments of Act on IPN of 2010), and the substantial effort to present the records needed by the IPN's lustration branch for the current proceedings as well as for the publication of the Catalogues of the Public Personalities, Communist dictatorship functionaries and Persons Affected. One of the important milestones of the institutional history of IPN Archives was the lawmakers' decision of 2016 to declassify all of the records pointed in the Act on Institute as belonging to its archival resources and to liquidate the so-called 'restricted resource'  (i.e. the part of IPN archival resource that was restricted by the state's protection services and therefore not released for the public).