A glass ring 2, which includes an inner peripheral surface 4, an outer peripheral surface 3 and annular contacting surfaces 5 for contact with magnetic disks and is formed in a ring shape having a rectangular vertical cross-section, is fabricated. The glass ring has at least the contacting surfaces 5 lapped and then etched to have a desired surface roughness so as to improve a surface property. Additionally, the roughened surfaces of the etched contacting surface have an electrically conductive film 6 formed thereon, providing a spacer ring.