To perform mechanical analysis of a structure having a complicated structure in the range of a realistic operation load.

An analyzer includes a whole mode operation processing part 24 for calculating a characteristic mode relative to the whole structure by using a finite element model wherein each node set relative to the structure is in a free support state; a local mode operation processing part 26 for calculating a characteristic mode up to a higher frequency than the whole mode operation processing part 24 relative to the structure by using a finite element model wherein each node other than nodes on the periphery of a partial structure in consideration of local deformation in the structure is in a restraining support state; and a mode synthesis-orthogonalization part 28 for synthesizing and orthogonalizing the characteristic mode acquired by the whole mode operation processing part 24 with the characteristic mode acquired by the local mode operation processing part 26.