To provide a method and a device for manufacturing a printing plate by means of vibrational energy.

The method and the device for manufacturing a letterpress printing plate out of sensitizing elements including a partially liquefiable photopolymerizable composition layer are dealt. The method includes: (a) the process for forming a liquefied material by heating the outside surface of the photopolymerizable composition layer up to the temperature enough high for liquifying some part of the layer; and (b) the process for removing the liquefied material, wherein the heating process is executed by utilizing vibration-inducing frictional energy.