A wire-spacing verification method for a computer includes calculating a characteristic impedance of each wire model disposed in a substrate model on a basis of a propagation rate of a signal in the wire model and rise time or fall time of an element model for transmitting the signal, calculating a reference impedance for predetermined sections, creating a distribution map in a direction of a section length with respect to the characteristic impedance of each of the sections for which the reference impedance is calculated, calculating an index indicating a degree of mismatch with the reference impedance, on a basis of the created distribution map, and making an approval/denial determination on the wire model on a basis of the index.