A halftone phase shift photomask blank has on a transparent substrate, a first film serving as a halftone phase shift film, a second film serving as a light shielding film, a third film serving as a hard mask film, and a fourth film. The first and third films are formed of silicon-containing materials which are resistant to chlorine base dry etching and removable by fluorine base dry etching. The second and fourth films are formed of silicon-free, chromium-containing materials which are resistant to fluorine base dry etching and removable by chlorine base dry etching.