To suppress occurrence of grinding unevenness (surface unevenness) on a peripheral portion of a glass substrate after grinding, due to insufficient feeding of a grinding liquid to a peripheral portion of a grinder.

There is provided a method of feeding the grinding liquid for use in single-surface grinding of the glass substrate G, according to which the glass substrate G is sucked and held by a suction pad 6 formed of a porous soft resin sheet, which is stuck to a surface of a pressing disk 1 rotatable about a swinging rotation shaft 8, and then the glass substrate G is pressed onto a grinding cloth 9 laid on the rotating grinder 2 by the pressing disk 1, followed by grinding the glass substrate G while feeding the grinding liquid in the form of slurry containing water and grinding grains dispersed therein. According to the method, the grinding liquid is fed from a feeding port at the center of the grinder, and from at least one or more liquid feeding nozzles 4 arranged along a peripheral edge of the pressing disk and rocked together with the pressing disk 1.