There is provided a platemaking method of forming relief based on relief pattern data in a printing plate to be pressed on a printing matter, and the platemaking method includes steps of: estimating distribution of printing pressure of the printing plate pressed on the printing matter on the basis of image data and distribution data of plate thickness; calculating an amount of correction of engraving shape data on the basis of the distribution of printing pressure; correcting the engraving shape data on the basis of the amount of correction; and acquiring exposure amount data from the engraving shape data corrected. It is possible to form relief in consideration of deformation of a printing plate in accordance with the distribution of printing pressure in the printing plate to favorably print and reproduce an image on a printing medium.