An inspection-required product selection method and program for minimizing the number of investigation steps at the time of a defect occurrence for a product placed on the market are disclosed. A combination of product lots to be inspected is assumed based on the information on the material lots used for a product lot scheduled for production for a predetermined future period and the number of the product lots inspected during the same period. The number of the material lots not included in the product lots to be inspected is totalized for each product lot, and the statistical values are calculated for all the conceivable combinations of the product lots. The combination of the product lots optimizing the statistical values is selected for inspection.