To provide an apparatus of compact structure for correcting the inclination of a printing plate.

An apparatus corrects the inclination of the printing plate (28) on a plate cylinder of a rotary press. A front fastening rail (24) for holding the front fringe of the printing plate and a rear fastening rail (26) for holding the rear fringe of the printing plate are provided. The front fastening rail can revolve around a revolving point (31) arranged approximately in the middle of the extension in the axial direction of a cylinder passage (25). A rear fastening device has a lower rail (36) guided in the axial direction, a revolving stripe piece (39) pivoted revolvably on the lower rail, and at least one fastening rail (26) pivoted revolvably in the circumferential direction by the revolving stripe piece.