Patent ID: 7798889

Claim:
A chamfering apparatus that chamfers at least one of edges of an outer periphery or an inner periphery of a glass substrate, the glass substrate having either a disk shape or a disk shape having a center circular hole, the chamfering apparatus comprising: a grindstone having a cylindrical hollow end portion; a grindstone driving unit that rotates the grindstone around an axis of the cylindrical hollow end portion; a substrate rotation-driving unit that rotates the glass substrate around either an axis of the outer periphery or an axis of the center circular hole; and a pressing unit that presses the grindstone to the glass substrate such that an annular end surface of the grindstone contacts an edge of either the outer periphery or the inner periphery of the glass substrate while the cylindrical hollow end portion of the grindstone faces either the outer periphery or the inner periphery of the glass substrate, wherein the annular end surface of the grindstone is one of: concavely curved and tilted such that an axial length of the grindstone increases from an innermost radius of the grindstone to an outermost radius of the grindstone, or convexly curved and tilted such that the axial length of the grindstone decreases from the innermost radius of the grindstone to the outermost radius of the grindstone.