A system, a method, and a program for predicting a processing shape formed by a plasma process, including databases for apparatus condition, incident ion, incident radical, actual measurement, material property and surface reaction, as well as a trajectory calculation unit, and a surface shape calculation unit. The trajectory calculation unit calculates the trajectories of the respective ions incident on the surface of the substrate based on information and data obtained from the databases and from measurement data from an on-wafer monitoring sensor. Based on the calculation result by the trajectory calculation unit, the surface shape calculation unit calculates the change of the shape by referring to the data stored in the material property and surface reaction DB.