From the website:
"The Emanuel Ringelblum Jewish Historical Institute was formally established on January 1, 2009 by the Minister of Culture and National Heritage, as a new institution of culture. It is named in honor of Emanuel Ringelblum, the leader of the clandestine team gathering materials documenting Jewish life in the Warsaw ghetto under German Nazi occupation. The new Jewish Historical Institute is an immediate continuation of the Jewish Historical Institute (Zydowski Instytut Historyczny, ZIH) as a research institute, which was dissolved on December 31, 2008.
The predecessor of the present ZIH was founded in 1947 and for many decades pursued studies of Jewish history and culture. It gathered priceless collections of archival files, photographs, books, journals and art pieces being the heritage of the great Jewish community in Poland and a testimony to the Jewish life which flourished in Poland for several centuries. The most precious part of ZIH’s holdings is the Warsaw ghetto collection of reports and documents known as the Ringelblum Archive, included in the UNESCO Memory of the World register."
The institute has a library and houses a number of archives relevant to Polish-Jewish history including many materials in Yiddish.
The online catalog of the institute can be consulted here.