1. An ion implantation simulation apparatus for simulating movement of an ion particle to which a particle number is given, comprising: a group creation part to divide n ion particles (n≧3) into groups of at least three, according to the particle number; an individual area setting part to individually set up a calculation area, as an individual area, indicating an area for calculating movement of one of the n ion particles, for each of the groups divided by the group creation part, and to implant the one of the n ion particles into the individual area individually set up, for performing simulation; and a calculation part to calculate the movement of the one of the n ion particles implanted by the individual area setting part in order to simulate movement of the one of the n ion particles.