SELF-RESONANT COIL, CONTACTLESS POWER TRANSFERRING APPARATUS, AND VEHICLE

A self-resonant coil (110, 240) to be used in a non-contact electric power transfer device capable of at least one of electric power transmission and electric power reception by using magnetic field resonance, wherein a coil having a circular shape in a cross section thereof perpendicular to a direction where the coil extends, a circumferential length of the coil that defines the cross section being equal to a length of a line segment that defines a cross-sectional outer peripheral edge of the self-resonant coil (110, 240) when the self-resonant coil (110, 240) is observed in a cross section thereof perpendicular to a direction where the self-resonant coil (110, 240) extends is used as a virtual coil (440), and at least one of a radial width and an axial length of the self-resonant coil (110, 240) in the cross section thereof perpendicular to the direction where the self-resonant coil (110, 240) extends is smaller than a diameter of the cross section of the virtual coil.