PROBLEM TO BE SOLVED: To provide a bearing with a magnetic fluid seal in which a seal of a rolling body portion inside the bearing is reliably maintained, and which is excellent in handleability, and prevents outflow of magnetic fluid to prevent sealability from being decreased.SOLUTION: A bearing 1 with a magnetic fluid seal includes: a ring-shaped polar plate 14 that is attached so that a ring-shaped magnet 12 is opposite to a rolling body 7, and in which one of the outer surface of an inner ring 3 and the inner surface of an outer ring 5 is a stationary side, and a gap G is formed at the other surface; an outer ring side magnetic fluid 15a that is held between the outer ring 5 and the ring-shaped polar plate 14 and/or between the outer ring 5 and the ring-shaped magnet 12; and an inner ring side magnetic fluid 15b that is held between the inner ring 3 and the ring-shaped polar plate 14 and/or between the inner ring 3 and the ring-shaped magnet 12. The ring-shaped polar plate 14, to which the ring-shaped ma
