A photo mask blank comprising: a first film (12, 22) which is etchable by dry etching using fluorine and which is not substantially etched by dry etching using oxygen-containing chlorine; a second film (13, 23) which is a metal compound film mainly comprising chromium oxide, chromium nitride, or chromium oxynitride, or a metal film or an alloy film mainly comprising chromium, the second film is not substantially etched by the dry etching using fluorine and is etchable by the dry etching using oxygen-containing chlorine, the second film is stacked on the first film; and a third film (14, 24) which contains no chromium and contains a transition metal which is selected from molybdenum, tantalum, tungsten, zirconium, hafnium, vanadium, and niobium, the third film is etchable by dry etching using fluorine and dry etching using oxygen-containing chlorine, the third film is stacked on the second film, wherein an atomic configuration of the third film is such that the transition metal accounts for at least 10at% of a sum of the transition metal and silicon, the first film or the second film is a light blocking film, when the first film is the light blocking film, the first film is an antireflective film formed by stacking a plurality of silicon compounds with different compositions, when the second film is the light blocking film, the second film is an antireflective film formed by stacking a plurality of types of chromium with different compositions, and the first film is formed of a silicon compound mainly comprising silicon oxide, silicon nitride, or silicon oxynitride and in which metal is contained. a first film (12, 22) which is etchable by dry etching using fluorine and which is not substantially etched by dry etching using oxygen-containing chlorine; a second film (13, 23) which is a metal compound film mainly comprising chromium oxide, chromium nitride, or chromium oxynitride, or a metal film or an alloy film mainly comprising chromium, the second film is not substantially etched by the dry etching using fluorine and is etchable by the dry etching using oxygen-containing chlorine, the second film is stacked on the first film; and a third film (14, 24) which contains no chromium and contains a transition metal which is selected from molybdenum, tantalum, tungsten, zirconium, hafnium, vanadium, and niobium, the third film is etchable by dry etching using fluorine and dry etching using oxygen-containing chlorine, the third film is stacked on the second film, wherein an atomic configuration of the third film is such that the transition metal accounts for at least 10at% of a sum of the transition metal and silicon, the first film or the second film is a light blocking film, when the first film is the light blocking film, the first film is an antireflective film formed by stacking a plurality of silicon compounds with different compositions, when the second film is the light blocking film, the second film is an antireflective film formed by stacking a plurality of types of chromium with different compositions, and the first film is formed of a silicon compound mainly comprising silicon oxide, silicon nitride, or silicon oxynitride and in which metal is contained.