The present invention provides a presensitized plate, comprising: an aluminum
plate having an aluminum purity of not less than 99 wt %; and a photosensitive
layer formed on the surface of said aluminum plate, wherein a fatigue fracture
strength of the presensitized plate after a heat treatment at 300 C. for
7 minutes is not less than 75% of the fatigue fracture strength thereof before
the heat treatment. The presensitized plate is excellent in efficiency and stability
of a roughening treatment, and is capable of preventing generation of fatigue fracture
of the lithographic printing plate during printing even if a burning treatment
has been made on lithographic printing plate.