There are two theories to explain the origin of butsudan; one refers to 'jibutsudo' (small private buildings or rooms used by noble men to enshrine their own Buddhist images and for their own personal spiritual edification) and another to 'tamadana' (alters dedicated to spirits of ancestors).
仏壇の起源については「持佛堂（ぢぶつどう）→仏壇説」と「魂棚（たまだな）→仏壇説」の2説ある。