To enhance the speed in a higher dimension by efficiently clustering a space in the higher dimension and to perform a similarity retrieval storing approximate information as short information without any waste, reducing the whole storage space, and reducing the frequency of the accesses to a processing such as the retrieval.

This multidimensional index creating device divides a multidimensional space into a plurality of regions and creates multidimensional indices according to the divided regions. A regular simple substance to be a reference is disposed in a position in the multidimensional space, spheres are disposed in the vertices of the disposed regular simple substance, and the multidimensional space is divided by the spheres.