Jan Baster was born in 1956 in Cracow. He is a graduate of the Faculty of Law and Administration of the Jagiellonian University (1978 – Master's degree in administration, 1981 – Master's degree in law).

In 1983, he was an assistant at the Faculty of Law of the Jagiellonian University and worked at the Organizational, Legal and Personnel Department of the Cracow Town Hall. In the years 1983–1985, he was also employed at the Department of Culture and Art of the Cracow Town Hall. In 1985–1987, he was the Head of the Culture, Physical Education, Sport and Tourism Department of the Town and Commune Office in Myślenice. He cooperated with the Cracow Regional Football Association.

In the years 1987–1989, Baster ran his own company. From 1989 to 1995, he was the Economic Manager, Administrative Director and Head of the Events Section of the Groteska Theater in Cracow. He was also a teacher of jurisprudence at a Youth Educational Center.

Baster was the editor-in-chief of the bimonthly “Sekretarz Gminy”. In addition, he organized numerous sporting and cultural events – including “Krakowskie Zaduszki Jazzowe” [Cracow Jazz Festival] – (1993, 1994, 1995) and the Festival of Swiss Culture “Kunstgegen das Klischee” – held in Cracow in 1994.

From 1995 to 1998, Baster was the Director of the Public Administration Improvement Program, the Director of the National Forum of Secretaries of Municipalities Office, and the Association of Local Government Secretaries at the Lesser Poland Institute of Local Government and Administration in Cracow. He was the Chairman of the Management Board at the Cracow Institute for Civil State Development.

Baster authored numerous conference papers on the ethics of public administration officials, and the administrative reform. He was the coordinator of programs for local government officials. For instance, in 1997, he supervised the “Polish Commune in the European Union” program (France – Pologne Foundation). In 1998, he was the coordinator of the “Polish Commune in Integration with the European Union” program –  PHARE FIESTA. He headed the Public Administration Improvement Programat the Institute of Civil State Development.

In the years 1999–2001, he was the Deputy Director of the Local Government Council Office at the Lesser Poland Voivodship Marshal's Office. 

Baster started his career at the IPN in 2001. In the years 2001–2006, he was the Head of the Security Department at the IPN’s prosecutorial division in Cracow. He was the Director of the Office of the IPN’s President, and later headed the Institute’s Katowice Branch. In the years 2007–2010, Baster held the post of the Managing Director of the Institute. From 15 October 2010, he was the Deputy Director of the IPN’s Cracow Branch. Baster was appointed Deputy President of the Institute of National Remembrance in 2017.

In 2009, the late President Lech Kaczyński awarded him with the Officer's Cross of the Order of Polonia Restituta.