A bidirectional contactless power supply device configured to supply power by an electromagnetic induction effect form a primary-side coil to a secondary-side coil and from the secondary-side coil to the primary-side coil, the primary-side coil connected in series to a resonance capacitor on a primary side, the secondary-side coil connected in series to a resonance capacitor on a secondary side, the primary-side coil and the secondary-side coil arranged with a gap, the bidirectional contactless power supply device comprising: a first power converter connected to the primary-side coil through the resonance capacitor on the primary side; a second power converter connected to the first power converter; a third power converter connected to the secondary-side coil through the resonance capacitor on the secondary side; and a controller (71, 72) which controls the first power converter, the second power converter, and the third power converter, wherein the first, second, and third power converters (61, 62, 63) perform operation to convert direct current to alternating current and operation to convert the alternating current to the direct current under the control of the controller (71, 72); the second power converter converts the alternating current supplied from a commercial power source to the direct current, the first power converter converts the direct current input from the second power converter to high-frequency alternating current to output to the primary-side coil, and the third power converter converts the high-frequency alternating current input from the secondary-side coil to the direct current to supply to an electric storage device when the power is supplied from the primary-side coil to the secondary-side coil; the third power converter converts the direct current supplied from the electric storage device to the high-frequency alternating current to output to the secondary-side coil, the first power converter converts the high-frequency alternating current input from the primary-side coil to the direct current, and the second power converter converts the direct current input from the first power converter to the alternating current at a frequency of the commercial power source to output when the power is supplied from the secondary-side coil to the primary-side coil; characterized in that the first and second power converters (61, 62) are controlled by the controller for constant voltage driving of the primary-side coil when the power is supplied from the primary-side coil to the secondary-side coil, and the third power converter is controlled by the controller for constant current driving of the secondary-side coil when the power is supplied from the secondary-side coil to the primary-side coil. a first power converter connected to the primary-side coil through the resonance capacitor on the primary side; a second power converter connected to the first power converter; a third power converter connected to the secondary-side coil through the resonance capacitor on the secondary side; and a controller (71, 72) which controls the first power converter, the second power converter, and the third power converter, wherein the first, second, and third power converters (61, 62, 63) perform operation to convert direct current to alternating current and operation to convert the alternating current to the direct current under the control of the controller (71, 72); the second power converter converts the alternating current supplied from a commercial power source to the direct current, the first power converter converts the direct current input from the second power converter to high-frequency alternating current to output to the primary-side coil, and the third power converter converts the high-frequency alternating current input from the secondary-side coil to the direct current to supply to an electric storage device when the power is supplied from the primary-side coil to the secondary-side coil; the third power converter converts the direct current supplied from the electric storage device to the high-frequency alternating current to output to the secondary-side coil, the first power converter converts the high-frequency alternating current input from the primary-side coil to the direct current, and the second power converter converts the direct current input from the first power converter to the alternating current at a frequency of the commercial power source to output when the power is supplied from the secondary-side coil to the primary-side coil; characterized in that the first and second power converters (61, 62) are controlled by the controller for constant voltage driving of the primary-side coil when the power is supplied from the primary-side coil to the secondary-side coil, and the third power converter is controlled by the controller for constant current driving of the secondary-side coil when the power is supplied from the secondary-side coil to the primary-side coil.