A contactless power supplying system comprising: a power supplying device including a primary coil and a inverter adapted to apply current to excite and drive the primary coil; an appliance including a secondary coil, the secondary coil being adapted to generate an induced electromotive force using an alternate magnetic field generated by the current flowing to the primary coil, wherein the appliance is adapted to use the electromotive force generated at the secondary coil to supply power to a load; and characterized by:, a metal foreign object detection device including: a metal detection antenna coil arranged in the appliance, the metal detection antenna coil being different from the primary coil and the secondary coil; an oscillation circuit arranged in the appliance and adapted to generate current to excite and drive the metal detection antenna coil; a receiving antenna coil arranged in the power supplying device and adapted to detect a change in magnetic flux emitted from the metal detection antenna coil; and a detection circuit arranged in the power supplying device and adapted to receive from the receiving antenna coil a detection signal having a voltage waveform corresponding to the change in the magnetic flux, wherein: the secondary coil is accommodated in a housing of the appliance; the metal detection antenna coil is formed on a lower surface of the housing of the appliance, the lower surface of the housing of the appliance being provided as a power receiving surface that is adapted to come into contact with a setting surface of the power supplying device when the appliance is set on the setting surface; the primary coil is accommodated in a housing of the power supplying device; and the receiving antenna coil is formed on the setting surface of the power supplying device. a power supplying device including a primary coil and a inverter adapted to apply current to excite and drive the primary coil; an appliance including a secondary coil, the secondary coil being adapted to generate an induced electromotive force using an alternate magnetic field generated by the current flowing to the primary coil, wherein the appliance is adapted to use the electromotive force generated at the secondary coil to supply power to a load; and characterized by:, a metal foreign object detection device including: a metal detection antenna coil arranged in the appliance, the metal detection antenna coil being different from the primary coil and the secondary coil; an oscillation circuit arranged in the appliance and adapted to generate current to excite and drive the metal detection antenna coil; a receiving antenna coil arranged in the power supplying device and adapted to detect a change in magnetic flux emitted from the metal detection antenna coil; and a detection circuit arranged in the power supplying device and adapted to receive from the receiving antenna coil a detection signal having a voltage waveform corresponding to the change in the magnetic flux, a metal foreign object detection device including: a metal detection antenna coil arranged in the appliance, the metal detection antenna coil being different from the primary coil and the secondary coil; an oscillation circuit arranged in the appliance and adapted to generate current to excite and drive the metal detection antenna coil; a receiving antenna coil arranged in the power supplying device and adapted to detect a change in magnetic flux emitted from the metal detection antenna coil; and a detection circuit arranged in the power supplying device and adapted to receive from the receiving antenna coil a detection signal having a voltage waveform corresponding to the change in the magnetic flux, a metal detection antenna coil arranged in the appliance, the metal detection antenna coil being different from the primary coil and the secondary coil; an oscillation circuit arranged in the appliance and adapted to generate current to excite and drive the metal detection antenna coil; a receiving antenna coil arranged in the power supplying device and adapted to detect a change in magnetic flux emitted from the metal detection antenna coil; and a detection circuit arranged in the power supplying device and adapted to receive from the receiving antenna coil a detection signal having a voltage waveform corresponding to the change in the magnetic flux, wherein: the secondary coil is accommodated in a housing of the appliance; the metal detection antenna coil is formed on a lower surface of the housing of the appliance, the lower surface of the housing of the appliance being provided as a power receiving surface that is adapted to come into contact with a setting surface of the power supplying device when the appliance is set on the setting surface; the primary coil is accommodated in a housing of the power supplying device; and the receiving antenna coil is formed on the setting surface of the power supplying device. the secondary coil is accommodated in a housing of the appliance; the metal detection antenna coil is formed on a lower surface of the housing of the appliance, the lower surface of the housing of the appliance being provided as a power receiving surface that is adapted to come into contact with a setting surface of the power supplying device when the appliance is set on the setting surface; the primary coil is accommodated in a housing of the power supplying device; and the receiving antenna coil is formed on the setting surface of the power supplying device.