Provided is a mask blank which enables EB defect correction to be suitably applied and which further enables a reduction in the thickness of a light-shielding film. A mask blank 10 is used for producing a transfer mask adapted to be applied with ArF exposure light and has a light-shielding film 2 on a transparent substrate 1. The light-shielding film 2 is composed mainly of a material containing a transition metal, silicon, and at least one or more elements selected from oxygen and nitrogen. An etching rate of the light-shielding film by a fluorine-containing substance in a state of not being irradiated with charged particles is low enough to at least ensure etching selectivity with respect to an etching rate of the light-shielding film by the fluorine-containing substance in a state of being irradiated with the charged particles.