An automatic trace determination apparatus for automatically determining optimal positions of traces from pads to corresponding vias on a substrate using computation comprises: tentative determination means for tentatively determining a tentative target line with which tentative positions of bending points of traces are aligned; and final determination means for determining a final target line by correcting the tentative target line so that at least clearances between the adjacent traces and between the traces and vias adjacent to the corresponding traces can be secured, wherein the positions of intersection of the determined final target line and the traces from the pads are determined as bending points of the traces.