1. A mesh dividing device for performing a mesh dividing process of an analytical target model provided as three-dimensional CAD data into cuboids for numerical-analysis, comprising: a library for previously storing two or more kinds of parameter kits each including a maximum number of cuboids which defines the upper limit of the number of said cuboids and parameters for division-control for dividing said analytical target model into said cuboids; a selecting unit for selecting at least one of said two or more kinds of parameter kits stored in said library; and a mesh dividing unit for performing a mesh dividing process so as to divide said analytical target model, based on a parameter kit selected by said selecting unit and said three-dimensional CAD data, into cuboids of less than or equal to the maximum number of cuboids included in said selected parameter kit, and a conversion time estimating unit for estimating, based on said selected parameter kit, a conversion time required for said mesh dividing unit to perform a mesh dividing process for said analytical target model, wherein said display unit displays said conversion time estimated by said conversion time estimating unit.