A phase shift photomask is produced in the following manner. Before or after a light-shielding pattern is formed on a substrate, a transparent film serving as a phase shifter is coated onto the substrate, and the transparent film in a photomask-pattern-forming area exluding the peripheral area of the substrate is irradiated with energy rays. The irradiated portion of the transparent film is thus solidified. The unsolidified portion of the transparent film is removed by etching. A phase shifter pattern is thus formed on the substrate excluding the peripheral area of the substrate. Since the phase shifter pattern is not exposed at the peripheral area of the substrate, a dust which is usually made when the phase shifter pattern formed in this area cracks or peels off the substrate is not made. The number of defective photomasks to be produced can thus be reduced.