To provide a method for manufacturing a lithographic printing plate material using a plastic support, and a lithographic printing plate material with excellent dimensional reproducibility and development uniformity during printing.

This method for manufacturing the lithographic printing plate material 1 is to laminate apply a hydrophilic layer and a heat-sensitive imaging layer on a continuous band-like polyester film, and cut the laminate to a specified size by a grooved lower blade 11 and a circular upper blade 10 with 30 to 85° nose angle. In addition, the thickness of the lithographic printing plate material 1 is not less than 100 μm to not more than 300 μm, and the relationship of an interval (a mm) between the grooves of the lower blade 11 and an overlap level (b mm) of the upper/lower blades 11 and 10, of the cutting part, is represented by 0.05≤b/a≤0.5.

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