To provide a bearing device designed to make a rotational center coincident when a shaft rotates, and a polygonal scanner motor including the same.

In the bearing device, by a sleeve formed with a hallow portion, a shaft rotatably inserted into the hollow portion, a thrust plate for reducing the friction occurring when the shaft of the polygonal motor rotates by contacting with an end of the shaft, and a holder in which the sleeve and the thrust plate are arranged and is formed so that its contact surface will make point-contact with the thrust plate, the point-contact portion can be made to coincide with the rotational center on the same line, so that the bearing device and a polygonal scanner motor can be obtained which are capable of reducing vibration and noise.