To provide a manufacturing method of a glass substrate, which inexpensively manufactures a glass substrate having a desired warp, flatness, and profile irregularity.

A rough polishing process is included for polishing a glass sheet having a warp within a desired range, and in the rough polishing process, the glass sheet is polished by using a cerium oxide grindstone comprised of resin dispersed with cerium oxide particulates and having a compressive elasticity modulus larger than 370 MPa, and a tensile strain larger than 0.1%. Preferably, the glass sheet is manufactured by using the redraw method of heating and softening a matrix glass sheet, and extending it to a desired thickness.