A photomask blank including a transparent substrate, and at least one film (A) containing chromium and nitrogen and free of silicon and at least one film (B) containing silicon and oxygen, and free of a transition metal that are contacted to each other In the blank, when an intension of secondary ions is measured along a thickness direction of the films by a time-of-flight secondary ion mass spectrometry (TOF-SIMS), an intension of secondary ions derived from Cr2O5 is lower than an intension of secondary ions derived from SiN, at a position located at the interface or its vicinity of the film (A) and film (B) and having a maximum intensity of secondary ions derived from SiCrO5.