An offset printing plate precursor comprising a substrate having provided thereon a layer containing a substance capable of absorbing radiant rays and converting the radiant energy to heat energy, and a thin layer, wherein printing is performed by following the steps of: (a) subjecting the printing plate precursor to irradiation with active light, (b) subjecting the printing plate precursor to irradiation with light/heat convertible radiant rays or heat treatment, to thereby imagewise distribute a hydrophilic area and a lipophilic area of the thin layer, and (c) bringing the thin layer into contact with printing ink to form a printing plate in which the lipophilic area has received the printing ink, to thereby perform offset printing.