noun
Refers to the owner or holder of a collection, stored item, or asset, often in formal or institutional contexts (e.g., art collections, archives, securities).
この絵画の所蔵者は匿名を希望している。
The owner of this painting wishes to remain anonymous.
図書館は貴重書の所蔵者とし
The library is known as a holder of rare books.
保持者 means 'holder' in the sense of possessing a right, qualification, or record, whereas 所蔵者 is used for tangible items or collections.
Compound of 所蔵 (shozō, 'possession, collection') + 者 (sha, 'person'). The exact historical derivation is straightforward; the word is a modern formal term.