To efficiently prepare mesh data by automatically connecting parts in mesh data for performing the structural analysis of a structure to be formed by joining a plurality of parts without depending on the manual operation of an operator.

This mesh data preparing apparatus is provided with an edge extracting part 11 for extracting a pair of edges corresponding to the joint section of two mutually joining parts on the basis of three-dimensional design data, a mesh data preparing part 12 for preparing the mesh data of the structure for each of a plurality of parts forming the structure on the basis of three-dimensional design data, a node extracting part 13 for extracting nodes pertinent to the pair of edges extracted by the edge extracting part 11 from the mesh data, and a node connecting part 14 for connecting a node about one edge of the pair of edges to a node about the other edge.