Fluid dynamic bearing device

The density of a sintered metal bearing sleeve is adjusted to 80 to 95% relative to the true density, and the Young's modulus of the bearing sleeve is adjusted to 70 GPa or more. By increasing the density of the bearing sleeve and adjusting the Young's modulus of the bearing sleeve to 70 GPa or more in this manner, the change in size of the inside surface of the bearing sleeve can be reduced to 0.5 [mu]m or less when a 2-4 mm shaft member is supported.