Abstract: A hydrodynamic bearing apparatus comprises a shaft and a bearing having facing hydrodynamic surfaces therebetween. Hydrodynamic pressure generating grooves are disposed on at least one of the facing hydrodynamic surfaces of the shaft and bearing. The apparatus relatively rotatably supports the shaft and bearing by the hydrodynamic pressure from a lubricant fluid filled between the facing hydrodynamic surfaces. One of the shaft and bearing, on which the hydrodynamic pressure generating grooves are formed, are made of a metallic material whose thermal expansion coefficient is smaller than that of a copper containing material. A working layer made of the copper containing material is formed on the hydrodynamic surface side of the metallic material. The surface of the working layer functions as the hydrodynamic surface. The hydrodynamic pressure generating grooves are formed on the working layer.