Disclosed is a power feed system which can highly efficiently feed power to a power receiving unit from a power feed-side even though distance fluctuation or lateral shift occurs between a power feed-side helical coil and a power receiving-side helical coil. A distance measuring unit measures a inter-coil distance L1 between the power feed-side helical coil and the power receiving-side helical coil, and a control units, adjust capacitances of a power feed-side varactor and a power receiving-side varactor in accordance with the inter-coil distance L1 measured by the measuring unit.