In frame of computer simulation we study for the first time the magnetic superprism effect. We employ a simple square lattice model and restrict ourselves to lossless case. The photonic band structure for 2D PC built up of magneto-optical matrix with square holes is calculated. It is shown that an external magnetic field applied perpendicularly to the holes changes 2D PC band structure and thus propagation of light through PC.The effect exists even for a weak magneto-optical activity of the matrix but only for the definite set of model parameters. Thus, it makes possible to deflect a light beam by applying magnetic field without variation of frequency or initial angle of incidence.