To provide a method for removing a decomposition product which is generated in a laser engraving process for manufacturing a laser-engraved printing plate.

This method for manufacturing a laser-engraved printing plate is to engrave by laser the surface of an original laser-engraved printing plate with at least not less than one photosensitive resin cured product layer formed like a sheet or a cylinder, and manufacture the laser-engraved printing plate having an uneven pattern on the surface. In addition, this method is characterized in that the way to remove the decomposition product generated in the laser-engraving process includes the way to bring the decomposition product into contact with an ozone molecule.