To provide magnetic resonance image forming equipment using prepolarization technology to temporarily increase a low magnetic field.

Intervening MR image forming invites development of an open magnet, e.g. Such as a C-shaped magnet 1. In that case, it becomes increasingly hard to generate a large magnetic field for obtaining a good S/N ratio. To conquer this face, a prepolarization unit 7 is used, which uses, for instance, an HTSC magnet of YBCO, the magnet is carried near a patient to help the generation of the magnetic field, then drawn back to a position 8', to enable to detect a high frequency signal in the existence of the magnetic field of the C-shaped magnet 1.