Provided is a magnetic fluid sealed bearing unit that provides excellent handling ease and workability in incorporating the bearing unit into a rotary shaft portion and exhibits a stable sealing capability. A magnetic fluid sealed bearing unit of the present invention has an inner ring and an outer ring, each made of a magnetic material, a plurality of rolling members interposed between the inner ring and the outer ring, a magnetic seal mechanism arranged between the inner ring and the outer ring and configured to inhibit entry of foreign substances toward the plurality of rolling members, a non-magnetic inner ring-side support member fitted and retained on the inner ring, and a non-magnetic outer ring-side support member fitted and retained on the outer ring.