A non-contact power transmitting and receiving system, comprising: an inverter configured to generate a high-frequency voltage from a DC power supply on a power transmitting side; a power transmission coil connected to said inverter; a power reception coil configured to receive electric power from said power transmission coil in a contactless manner; a rectifier circuit configured to rectify AC power received at said power reception coil to a direct current; and a control unit (5, 6), wherein said inverter includes a first arm and a second arm as a plurality of arms (1A, 1B) connected in parallel across a power transmitting-side positive line and a power transmitting-side negative line which are supplied with a DC voltage from said DC power supply on the power transmitting side, and wherein said rectifier circuit includes a third arm and a fourth arm as a plurality of other arms (4A, 4B) connected in parallel across a power receiving-side positive line and a power receiving-side negative line which are supplied with a DC voltage rectified by said rectifier circuit, characterized in that the system further comprises a detection device configured to detect a phase difference between the output voltage and the output current of said inverter, and said control unit (5, 6) is configured to control said inverter and said rectifier circuit by adjusting at least one of switching timing of any arm of said inverter and switching timing of any arm of said rectifier circuit in accordance with said phase difference detected by said detection device, wherein, when the output current of said inverter leads the output voltage of said inverter in phase, said control unit (5, 6) is configured to control said rectifier circuit such that the switching timing of said third arm is delayed from a reference clock for said rectifier circuit. an inverter configured to generate a high-frequency voltage from a DC power supply on a power transmitting side; a power transmission coil connected to said inverter; a power reception coil configured to receive electric power from said power transmission coil in a contactless manner; a rectifier circuit configured to rectify AC power received at said power reception coil to a direct current; and a control unit (5, 6), wherein said inverter includes a first arm and a second arm as a plurality of arms (1A, 1B) connected in parallel across a power transmitting-side positive line and a power transmitting-side negative line which are supplied with a DC voltage from said DC power supply on the power transmitting side, and wherein said rectifier circuit includes a third arm and a fourth arm as a plurality of other arms (4A, 4B) connected in parallel across a power receiving-side positive line and a power receiving-side negative line which are supplied with a DC voltage rectified by said rectifier circuit, characterized in that the system further comprises a detection device configured to detect a phase difference between the output voltage and the output current of said inverter, and said control unit (5, 6) is configured to control said inverter and said rectifier circuit by adjusting at least one of switching timing of any arm of said inverter and switching timing of any arm of said rectifier circuit in accordance with said phase difference detected by said detection device, wherein, when the output current of said inverter leads the output voltage of said inverter in phase, said control unit (5, 6) is configured to control said rectifier circuit such that the switching timing of said third arm is delayed from a reference clock for said rectifier circuit.