A mask blank having a phase shift film and a light shielding film laminated on a transparent substrate. The phase shift film transmits ArF exposure light at a transmittance of from 2% to 30% and generates a phase difference of from 150° to 200°, is formed from a material containing Si and not substantially containing Cr, and has a lower layer (L) and an upper layer (U) laminated from the transparent substrate side. A refractive index n for layer L is below that of the substrate while n for layer U is higher, and layer L has an extinction coefficient k higher than that of layer U. The light shielding film includes a layer in contact with the phase shift film that is formed from a material containing Cr, has a n lower than that of layer U, and has an extinction coefficient k higher than that of layer U.