Magnetic hyperthermia is expected as a thermal ablation cancer therapy. For the induction heating of the nano scale magnetic beads, the required specifications of the high frequency magnet are 0.06 T and 200 kHz of the AC magnetic field with 5 minutes of the continuous or intermittent operation time. However, the magnet system requires the enough bore size for the cancer therapy. Addition to this, due to the skin effect of the conductor, the heating losses and the cooling systems of the magnet should be investigated. Moreover, the number of turns and the operating current should be optimized from the view point of the rated voltage and current of the high frequency power converter system. The objective of this work is to discuss the design considerations of the high frequency magnet for the magnetic hyperthermia applications. As a first step of this work, the authors carry out the design study on the conventional magnet case using copper conductors. The cooling of the magnet is based on the water cooling. The high frequency power converter system is composed of the resonance circuit between the magnets and the series capacitors. From the results of the electromagnetic and thermal analyses, this work shows an optimal magnet design and the coil arrangement including the design of the cooling system and the high frequency power converter system. Furthermore, in order to reduce the size and the heating losses of the magnet, the authors also clarify the technical targets and the problems of the superconducting magnets for the high frequency applications.