In the production of extreme ultraviolet photolithography masks, to produce a set of masks: mask blanks possibly containing defects are provided; an individual map of positions of defects in each mask blank is produced; a concatenated map of defects in a number of masks is produced by transposing, to a given useful zone common to all masks, positions of defects detected during mapping of various mask blanks; individual defect zones each associated with a respective defect and encircling said defect are defined; depending on design rules and on structure to be produced, an electronic version of layouts of the masks is produced, taking account locally, in the design rules, of the existence of each defect in the concatenated map to prevent critical elements from being placed in defect zones; and each mask is produced from any one of the mask blanks and with a respective layout thus obtained.