Rfid tag regulator circuit and the regulator circuit comprising

Object of the present invention to provide an improved noise margin of the regulator circuit. In the regulator circuit comprises: a bias circuit that generates a reference voltage based on the potential difference between the first power supply terminal and a second power supply terminal; and a voltage regulator, based on the reference voltage output from the bias circuit to the output terminal of the input potential. Bypass capacitor is provided between the node of the gate of the transistor connected to the power source terminal contained in the bias circuit.