PURPOSE: To prevent transfer of an nonimage part in a heat transfer layer, by forming a heat transfer layer contg. a diazo compd., a coupling component, a heat meltable material, and a photopolymerizable monomer.

CONSTITUTION: A finished support consisting of paper, synthetic paper, plastic film, or the like, and an adhesive layer, a mat layer, etc. is used for the support of a diazo type heat transfer master. A diazo type copying material capable of forming a diazo dye of a heat transfer dye on coupling reaction can be used alone or mixed for a diazo compound and a coupling component. As a photopolymer, at least one of a photoreactive resin contg. an UV absorber, etc. is used as a photopolymerizable material.