To provide a method of manufacturing an optical lithographic mask to be used in an optical lithographic system to manufacture a semiconductor integrated circuit or the like.

A phase-shifting optical lithographic mask is made by a method of manufacturing a set of phase-shifting shape bodies 11 arranged in a phase- shifting area and a set of strengthened alignment marks 13 arranged in an alignment area of a set of phase-shifting shape body 11 and mask arranged in the phase-shifting area. Both of these sets are arranged on a single quartz slab 10. This method contains a separating step to self-align the alignment marks 13 to the phase-shifting shape bodies 11 as a result. All the phase-shifting shape bodies 11 are combined with all the alignment marks 13, and are patternized between a single step. All of these contain bottom part layers 11 and 13 having a common thickness such as becoming semitransparent to light radiation used in a common material and an optical system of an optical lithograph.