A spindle motor includes a rotor unit and a stator unit arranged to rotatably support the rotor unit about a central axis through a fluid dynamic pressure generated in a lubricant held within a bearing gap between the rotor unit and the stator unit. The bearing gap has an annular opening coaxial or substantially coaxial with the central axis, the lubricant defining a capillary seal near the opening within the bearing gap. An oil buffer continuously expanding outwards from the opening of the bearing gap is provided between the rotor unit and the stator unit, the oil buffer being used in temporarily storing the lubricant when the lubricant is filled into the bearing gap, and an oleophobic treatment is performed on a surface of the rotor unit and a surface of the stator unit outside the oil buffer.