An exposure mask fabrication method includes measuring and storing defect position data, for each EUV exposure mask blank, that indicates the position of at least one defect in each of plural EUV exposure mask blanks, inputting pattern data defining a figure pattern to be written, searching, when the figure pattern is written, in plural EUV exposure mask blanks, an EUV exposure mask blank where the figure pattern can be arranged such that the number of defects not located in a light shielding region is less than or equal to a threshold value, based on the arrangement position of the figure pattern in the pattern data, using the defect position data for each EUV exposure mask blank, and writing the figure pattern on a searched EUV exposure mask blank such that the number of defects not located in the light shielding region is less than or equal to the threshold value.