It stores about twenty thousand items of legacy historical materials of the Konoe family, which was an honorable Kuge (court nobles) family and the head of Sekke (the five regent houses), such as ancient writing, old books, records, diaries, letters, and antique artworks.
公家の名門で「摂家」の筆頭である近衛家伝来の古文書（こもんじょ）、典籍、記録、日記、書状、古美術品など約20万点に及ぶ史料を保管している。