A wireless power supply system for lighting comprising: a power transmission unit comprising a power transmission coil, said power transmission coil being configured to generate an AC magnetic field in response to a supplied AC power, and an AC source section (13, 13A) configured to supply the AC voltage to said power transmission coil; and a power reception unit comprising a power reception coil, said power reception coil being configured to receive an electric power from said power transmission unit through an electromagnetic induction due to the AC magnetic field generated by said power transmission coil, wherein said power reception unit comprises a power circuit, a receive-side control section and a rectification section configured to rectify an output voltage of said power reception coil and to output a rectified voltage to said power circuit, said power circuit being configured to receive an output power from said power reception coil and to perform Buck-Boost operation so as to output a predetermined electric power to a lighting load, said receive-side control section being configured to control the Buck-Boost operation of said power circuit, wherein said power circuit is configured to be capable of boosting and stepping-down of the output power from said power reception coil, characterized in that said power reception unit further comprises a ripple measurement section configured to measure a ripple component in an input or output of said power circuit, and a signal transmitting section configured to transmit the measurement result of the ripple component to said power transmission unit, wherein said power transmission unit further comprises a signal receiving section configured to receive the measurement result transmitted from said signal transmitting section, and said power transmission unit is configured, when said ripple component is larger than a predetermined threshold, to increase at least one of an amplitude and a frequency of the AC voltage which is supplied to said power transmission coil from said AC source section (13, 13A). a power transmission unit comprising a power transmission coil, said power transmission coil being configured to generate an AC magnetic field in response to a supplied AC power, and an AC source section (13, 13A) configured to supply the AC voltage to said power transmission coil; and a power reception unit comprising a power reception coil, said power reception coil being configured to receive an electric power from said power transmission unit through an electromagnetic induction due to the AC magnetic field generated by said power transmission coil, wherein said power reception unit comprises a power circuit, a receive-side control section and a rectification section configured to rectify an output voltage of said power reception coil and to output a rectified voltage to said power circuit, said power circuit being configured to receive an output power from said power reception coil and to perform Buck-Boost operation so as to output a predetermined electric power to a lighting load, said receive-side control section being configured to control the Buck-Boost operation of said power circuit, wherein said power circuit is configured to be capable of boosting and stepping-down of the output power from said power reception coil, characterized in that said power reception unit further comprises a ripple measurement section configured to measure a ripple component in an input or output of said power circuit, and a signal transmitting section configured to transmit the measurement result of the ripple component to said power transmission unit, wherein said power transmission unit further comprises a signal receiving section configured to receive the measurement result transmitted from said signal transmitting section, and said power transmission unit is configured, when said ripple component is larger than a predetermined threshold, to increase at least one of an amplitude and a frequency of the AC voltage which is supplied to said power transmission coil from said AC source section (13, 13A).