An improved method for selectively curing a liquid photosensitive resin by masking exposure is provided, wherein rough, uneven or irregular contact is provided directly or indirectly between the masking film and the substrate. Due to this feature, no interfacial cohesion occurs between the lower surface of the masking film facing the substrate and the upper surface of the substrate facing the masking film. Thus, there are no air pockets formed between the two surfaces. Therefore, there is no danger that the substrate will be caused to protrude into the resin layer so that the ultimate printing plate would have an undesirable local decrease in thickness. As a result, by the method of the present invention, a printing plate having a high degree of uniformity in thickness, can be obtained with reproducibility.