Planographic printing plate

A planographic printing plate precursor comprising:

• an aluminum substrate which has been subjected to a roughening treatment and an anodizing treatment;
• and
• a photosensitive layer which is provided on a surface of said substrate, and which contains an infrared absorbing agent and a water-insoluble and alkali aqueous solution-soluble polymer compound, and whose solubility in an alkali developing solution varies by infrared laser exposure,
• wherein said substrate is obtained by electrochemically roughening an aluminum alloy plate which contains 0.05 to 0.5% by weight of Fe, 0.03 to 0.15% by weight of Si, 60 to 300 ppm of Cu, 100 to 400 ppm of Ti and 10 to 200 ppm of Mg, contains 1 to 100 ppm of at least one element selected from the group of elements consisting of Li, Na, K, Rb, Cs, Ca, Sr, Ba, Sc, Y, Nb, Ta, Mo, W, Tc, Re, Ru, Os, Co, Rh, Ir, Pd, Pt, Ag, Au, C, Ge, P, As, S, Se, Te and Po, and has an aluminum purity of 99.0% by weight or more.