A method and a program for predicting a processing shape by a plasma process, the method including: a conditions-setting step (STEP 11) for setting conditions relevant to an object to be processed, process conditions including a cycle number provided that an etching process and a deposition process are taken as one cycle, and conditions relevant to simulation; an etching process surface transition amount calculating step (STEP 12) for calculating a surface transition amount by plasma etching based on etching process conditions; and a deposition process surface transition amount calculating step (STEP 13) for calculating a surface transition amount by plasma deposition based on deposition process conditions, wherein the etching process surface transition amount calculating step (STEP 12) and the deposition process surface transition amount calculating step (STEP 13) are repeated for the cycle number set in the conditions-setting step (STEP 11), thereby obtaining a processing shape by the the Bosch process.