A vehicle opening-and-closing member locking-and-unlocking apparatus comprising: an antenna including a series resonance circuit having a resonance capacitor and an antenna coil connected in series and an impedance regulating resistance connected in parallel to the antenna coil, the resonance capacitor side being connected in parallel to a first connecting line, the antenna coil side being connected to a second connecting line, and the antenna transmitting authentication information for locking and unlocking a vehicle opening-and-closing member to a portable device carried by a user of the vehicle by resonance with an antenna drive signal output from an ECU via the first connecting line and the second connecting line, wherein a resistance value of the impedance regulating resistance is larger than a reactance value of the antenna coil; a human detection IC configured to detect contact to a human detecting area on the vehicle opening-and-closing member by the user by operating with the antenna drive signal as power source when the antenna is driven and thus a direct current power source voltage is not supplied from the ECU via the first connecting line; and a rectifier circuit configured to AC/DC convert the antenna drive signal and supply the converted signal to the human detection IC wherein the impedance regulating resistance is divided into a first voltage dividing resistance and a second voltage dividing resistance, and the divided voltage obtained by dividing the antenna resonance voltage with the first voltage dividing resistance and the second voltage dividing resistance is output to a power source terminal of the human detection IC via a voltage dividing rectifier diode, and an anode of the voltage dividing rectifier diode is connected between the first voltage dividing resistance and the second voltage dividing resistance of the impedance regulating resistance, and a cathode of the voltage dividing rectifier diode is connected to the power source terminal of the human detection IC. an antenna including a series resonance circuit having a resonance capacitor and an antenna coil connected in series and an impedance regulating resistance connected in parallel to the antenna coil, the resonance capacitor side being connected in parallel to a first connecting line, the antenna coil side being connected to a second connecting line, and the antenna transmitting authentication information for locking and unlocking a vehicle opening-and-closing member to a portable device carried by a user of the vehicle by resonance with an antenna drive signal output from an ECU via the first connecting line and the second connecting line, wherein a resistance value of the impedance regulating resistance is larger than a reactance value of the antenna coil; a human detection IC configured to detect contact to a human detecting area on the vehicle opening-and-closing member by the user by operating with the antenna drive signal as power source when the antenna is driven and thus a direct current power source voltage is not supplied from the ECU via the first connecting line; and a rectifier circuit configured to AC/DC convert the antenna drive signal and supply the converted signal to the human detection IC wherein the impedance regulating resistance is divided into a first voltage dividing resistance and a second voltage dividing resistance, and the divided voltage obtained by dividing the antenna resonance voltage with the first voltage dividing resistance and the second voltage dividing resistance is output to a power source terminal of the human detection IC via a voltage dividing rectifier diode, and an anode of the voltage dividing rectifier diode is connected between the first voltage dividing resistance and the second voltage dividing resistance of the impedance regulating resistance, and a cathode of the voltage dividing rectifier diode is connected to the power source terminal of the human detection IC.