1. A method for determining alignment parameters for positioning each of a plurality of processing areas arrayed on an object with respect to a predetermined processing position, which method for determining the alignment parameters comprises a first step of performing position measurement for any sample points set in each processing area under predetermined alignment parameters through opto-electric detection and statistical processing based on measured positions and design positions of said sample points to obtain reference computation results, a second step of positioning and processing each processing area at said predetermined processing position based on said reference computation results, then measuring a first processing error of said processing area to obtain reference processing results, a third step of changing at least part of said predetermined alignment parameters and performing position measurement of any sample points set in each processing areas and statistical processing based on the measured positions and design positions of said sample points to obtain comparative computation results, and a fourth step of calculating a second processing error for each processing area, estimated when assuming said positioning and processing said processing area at said predetermined processing position based on said comparative computation results, using said reference computation results, said comparative computation results, and said reference processing results, wherein said third step includes: a sixth step of using signal waveforms obtained by said opto-electric detection at said first step to change at least part of said predetermined alignment parameters and obtain a plurality of said comparative computation results and a seventh step of comparing the plurality of comparative computation results obtained at said sixth step and said reference computation results and selecting candidates of said comparative computation results to be used in said fourth step based only on said comparison results.