Abstract: A mask blank that can be formed without causing a shape defect in a transfer pattern having a high resolution. A mask blank (10) includes a transparent substrate (11), an etched layer (14) located above the transparent substrate (11), a suppression layer (20) located above the etched layer (11) and formed using a first chemical amplification resist, and a mask layer (15) located above the suppression layer (20) and formed using a second chemical amplification resist. The mask layer (15) functions to generate acid with the second chemical amplification resist when receiving exposure light and change solubility of the mask layer (15) with respect to a development liquid. The suppression layer (20) functions to generate acid with the first chemical amplification resist when receiving the exposure light through the mask layer (15) and obtain insolubility of the mask layer (15) with respect to the development liquid.