A dynamic-pressure fluid bearing comprises bearing parts formed by a pair of dynamic-pressure surfaces. One of the dynamic-pressure surfaces of the bearing parts is a polyamideimide coating thicker than 3 mu m and the other surface is metal. The bearing is particularly applicable to driving motors for polygon mirrors. In addition, a so-called particle removing function is added to one or more of the surfaces of the bearing parts or a position nearby that causes easier removal of dust and other particles accumulated on the parts.
