PURPOSE: To obtain a highly detailed digital image with high sensitivity by a simple developing method using a recording medium using a polymerizable resin.

CONSTITUTION: An image recording medium is obtained by providing a thermally polymerizable recording layer containing a photothermal conversion substance, a thermally polymerizable resin and a thermal polymerization initiator on a support and further providing a water-soluble protective layer and a sheet for transferring an undeveloped part on the thermally polymerizable recording layer in succession. At the time of the formation of an image, the image recording medium is imagewise irradiated with light and developed by a method selected from transfer, peeling and the immersion in a developing soln.