This invention is to detect defective products of semiconductor devices with high accuracy even when the characteristics of the semiconductor devices vary according to their positions on each of wafers. A screening method includes the steps of measuring respective electrical characteristic values of a plurality of semiconductor devices included in a wafer; acquiring respective positional information of the semiconductor devices over the wafer; subtracting components relatively gently varying over the surface of the wafer, of variations in the electrical characteristic values of the semiconductor devices from the respective electrical characteristic values of the semiconductor devices to thereby correct the respective electrical characteristic values of the semiconductor devices; generating distributions of the post-correction electrical characteristic values with respect to the semiconductor devices; and detecting semiconductor devices in which the post-correction electrical characteristic values assume outliers, out of the semiconductor devices, based on the distributions.