The present invention provides an exposure processing method of a planographic printing plate comprising: providing an image recording layer containing a polymerizable compound which is solid at the room temperature, a polymerization initiator, and a light-to-heat converting agent, and a microcapsule encapsulating at least one of the monomer and the polymerization initiator, such that the light energy quantity absorbed in the lower part of the image recording layer is more than the light energy quantity absorbed in the upper and middle parts of the image recording layer; exposing the image recording layer, and thereafter post-heating the image recording layer at a temperature in a range equal to or above the melting point of the monomer and below the glass transition point of the wall of the microcapsule. As a result, the printing resistance of a planographic printing plate is enhanced.