An image stabilizer includes: an optical system movable in a plane perpendicular to an optical axis (“orthogonal plane”) and correcting image blur; a movable member holding the optical system and movable relative to a fixed member in an orthogonal plane; a guide guiding the movable member while preventing from rotating in an orthogonal plane; three first balls rollably interposed between the fixed and guide members; two second balls rollably interposed between the guide and movable members; one third ball rollably interposed between the fixed and movable members; a biasing unit biasing the movable member toward the fixed member; and a drive unit driving the movable member relative to the fixed member in two directions perpendicular to the optical axis, wherein in an orthogonal plane, two of the first balls are rollable only in first direction; the second balls are rollable only in second direction different from the first direction.