A design support device includes a unit that accepts registration of normal CAD data with a past record and violation CAD data determined to have violated portion with respect to three-dimensional CAD data, a unit that acquires a parameter related to a design rule from CAD data to be evaluated, a unit that calculates a statistical value of the acquired parameter and calculates a value of an influence degree t that explains a violation of each parameter, and a unit that presents a scatter diagram plotting normal CAD data and violation CAD data to be evaluated and a boundary line subjected to cluster analysis, on a two-dimensional coordinate system, according to a combination of parameters designated by a user (evaluator).