A layout verification device according to the present invention includes a layout verification unit that outputs a first error graphic corresponding to an area where there is an inconsistency with a design rule in a first layout pattern, and includes a target error graphic setting unit that sets a processing target area including the first error graphic, an error graphic search unit that searches a second error graphic included in a processing target area of a second layout pattern where verification by the layout verification unit has already been performed, and an error graphic equivalence judgment unit that judges that the first error graphic and the second error graphic are non-equivalent when a second target vertex coordinate of the second error graphic does not match any one of a plurality of peripheral vertex coordinates set in grid intersections adjacent to the first target vertex coordinate of the first error graphic.