PURPOSE: To perform plate making by the image signal heat corresponding to image data by successively providing a release layer, a low heat-resistant adhesive polymer layer and a nonwoven fabric on a high heat-resistant sheet.

CONSTITUTION: A release layer 2 composed of silicone oil is provided on a high heat-resistant sheet 1 such as a polyester film and a low heat-resistant sheet 3 composed of polyolefin is provided thereon and a nonwoven fabric 4 composed of rayon or nylon is further provided thereon to form a sheet for forming a thermal printing plate. The heat of a thermal head 5 by an image signal is applied to the back surface of said sheet and the low heat-resistant sheet is partially melted and perforated to form predetermined image forming opening parts 6.