In determining a relative position between a chip lattice including rectangular cells, each of which has a size of a chip to be formed on a substrate and an effective area on the substrate, one representative cell in the chip lattice is divided into a plurality of partial areas in accordance with an existing area, of a representative point of the effective area, in which chip sets trimmed from the chip lattice with the effective area are identical. A partial area corresponding to a chip set including a maximum number of chips is specified from the plurality of partial areas, and the representative point is set in the specified partial area.