1. A mesh generation system comprising: one or more processors; one or more memory devices; a mesh know-how database generating unit stored on the one or more memory devices and executable by the one or more processors, having an evaluation point designating unit which designates an evaluation point or an evaluation site on an analysis target shape; a multiple-mesh generating unit stored on the one or more memory devices and executable by the one or more processors, which generates a plurality of meshes of different element sizes with respect to the analysis target shape; an analysis calculation unit stored on the one or more memory devices and executable by the one or more processors, which analyzes plural analysis model data created with the plurality of meshes of different element sizes, the mesh know-how database generating unit generating a relation among mesh element size, analysis result and calculation time; a mesh know-how database which stores the generated relation among mesh element size, analysis result and calculation time; an input unit stored on the one or more memory devices and executable by the one or more processors, which inputs a required accuracy or calculation time limit; a mesh element size search unit stored on the one or more memory devices and executable by the one or more processors, which searches for a mesh element size that meets the required accuracy or calculation time limit, based on the relation among mesh element size, analysis result and calculation time registered in the mesh know-how database; an analysis model setting unit stored on the one or more memory devices and executable by the one or more processors, which sets the mesh element size found by the search, to an analysis model; and a display unit stored on the one or more memory devices and executable by the one or more processors, which reads the relation among mesh element size, analysis result and calculation time from the mesh know-how database and displays the relation among mesh element size, analysis result and calculation time, wherein the mesh element size and the analysis result registered in the mesh know-how database are read, an error rate of the analysis result at each node of the mesh having the mesh element size found by the search is calculated, and the error rate is displayed as a distribution chart on the analysis target shape.