MAGNETIC-FIELD RESONANCE POWER TRANSMISSION DEVICE AND MAGNETIC-FIELD RESONANCE POWER RECEIVING DEVICE

To improve the efficiency of electric power transmission in a magnetic resonance wireless electric power transmission system in which electric power transmission by magnetic resonance is performed from an electric power-transmitting apparatus to an electric power-receiving apparatus. A magnetic resonance electric power-transmitting apparatus (10) in the magnetic resonance wireless electric power transmission system (1) includes a resonance coil (11), an electric power-supplying unit (12) which supplies electric power to the resonance coil (11) to cause the resonance coil to generate a magnetic field, a magnetic material (13) which varies a magnetic field generated by the resonance coil (11), and a position adjustment unit (14) which adjusts a positional relationship between the resonance coil (11) and the magnetic material (13).