Power supply side equipment comprises a high-frequency power supply, a matching box, a primary side resonance coil, an output impedance variable unit, a matching state detection unit, and a control unit. By a magnetic field resonance, the primary side resonance coil transmits power in a non-contact manner to a load through a secondary side resonance coil. At least the matching box, the primary side resonance coil, the secondary side resonance coil, and the load constitute a resonance system having a resonant frequency. The matching state detection unit detects the matching state between the input impedance of the resonance system and the output impedance of the high-frequency power supply at the resonant frequency. The control unit adjusts the output impedance variable unit and the matching box according to the detection result by the matching state detection unit so that the input impedance of the resonance system and the output impedance of the high-frequency power supply match each other.