A die is produced based on die model data. The produced die is corrected. The corrected die is three-dimensionally measured by a measuring tool to produce measured three-dimensional die data. A polygonal surface represented by the measured three-dimensional die data and a model surface represented by the die model data are compared with each other. The polygonal surface is brought into proximity to the model surface, and the absolute values of the distances between a plurality of pairs of measuring points on the polygonal surface and corresponding points on the model surface are calculated. The die model data are corrected based on the absolute values of the distances.