To provide a built-in type printing-plate making method which enables the constitution of a simple printing machine and has an enlarged application field, and an apparatus for the method.

At least one plate cylinder, a printing image part forming device, a thermal transfer ribbon set between the printing image part forming device and the plate cylinder to transfer printing image part information to the plate cylinder, a device for fixing the printing image part information to the plate cylinder by heat, and a cleaning device for eliminating the printing image part information on the plate cylinder are provided as a premise. A printing rubber blanket 3 is fitted detachably to the plate cylinder 2 and made to be able to contact an inking mechanism 10, and the printing image part information can be transferred directly from the thermal transfer ribbon 7 to the blanket 3. The blanket 3 has a base layer of a stable size and can contact a printing material in a printing clearance 11.