Thin-profile spindle motor. Single hydrodynamic-pressure thrust and radial bearings are established about a thrust plate on the end of the motor shaft, encompassed by a cylindrical casing. Hydrodynamic pressure-generating grooves scored on either of the thrust plate end faces, or either of the inner faces of the casing ends opposing the thrust plate end faces, are a component of the single thrust bearing. A micro-gap clearance for the thrust bearing, retaining lubricant continuously with the radial bearing, is established on whichever side of the thrust plate the thrust bearing is formed. Like grooves scored on either the thrust plate circumferential surface, or the casing inner cylindrical surface by which it is opposed at a micro-gap clearance, the clearance itself, and lubricant retained therein form the single radial bearing. Means for magnetically counterbalancing the thrust hydrodynamic-pressure are provided between rotor hub and the stator or casing.