1. A method of processing a plurality P of semiconductor wafers, the method comprising: sequentially performing n (first to n-th) process steps with respect to a plurality P of wafers, wherein the order of processing the P wafers is different in each of at least two of the n process steps; calculating characteristic parameter values for the plurality P of respective wafers; calculating first to n-th relations that indicate relationships between the first to n-th process orders and the characteristic parameter values; performing a Fourier transform on the first to n-th relations so as to calculate first to n-th conversion relations; and determining patterns of the first to n-th relations using the first to n-th conversion relations.