Patent ID: 7354860

Claim:
A method of manufacturing a mask blank, comprising: preparing a rectangular substrate formed with a thin film becoming a transfer pattern to be transferred to a body to be transferred, and also formed with a resist film by applying resist liquid on the thin film and drying the resist film thus applied; removing an unnecessary resist film formed in a removed area provided on a peripheral edge of a main surface of the substrate by using chemical liquid; and heating the resist film formed in a non-removed area which is a main surface of the substrate and an area other than the removed area, wherein in the unnecessary film removing step, a cover member is disposed in a main surface of the substrate formed with the resist film so as to form a prescribed gap with a main surface of the substrate in the removed area, further the substrate is rotated at the rotation speed R 1 to dissolve the unnecessary resist film by feeding the chemical liquid in the gap, thereafter, the feeding of the chemical liquid is stopped, further the substrate is rotated at the rotation speed higher than the prescribed rotation speed, and the unnecessary resist film thus dissolved is removed outside the substrate, wherein the substrate is rotated when removing the dissolved unnecessary resist film outside the substrate and drying the area from which the resist film is removed, at the rotation speed R 2 capable of suppressing variations in removed width in each side of the substrate, the variation being caused by the difference in centrifugal force applied on the dissolved resist film in a direction along each side of the peripheral edge of the main surface of the substrate, and thereafter, the substrate is rotated at a prescribed rotation speed R 3 so as to dry the area from which the resists film is removed.