1. A mesh generation system comprising: a mesh know-how DB generating unit 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 which generates meshes of plural mesh sizes with respect to the analysis target shape, and an analysis calculation unit which analyzes plural analysis model data created with the plural types of mesh size, the mesh know-how DB generating unit generating a relation among mesh size, analysis result and calculation time to be stored in a mesh know-how DB; a mesh know-how DB which stores the relation among mesh size, analysis result and calculation time; an input unit which inputs a required accuracy or calculation time limit; a mesh size search unit which searches for a mesh size that meets the required accuracy or calculation time limit, based on the relation among mesh size, analysis result and calculation time registered in the mesh know-how DB; an analysis model setting unit which sets the mesh size found by the search, to an analysis model; and a display unit which reads the relation among mesh size, analysis result and calculation time from the mesh know-how DB and displays the relation among mesh size, analysis result and calculation time.