An appliance comprising: an operation unit that is mounted in a case of the appliance and being supplied with alternating current power by an external power supply, the operating unit including at least one of a motor and a heating member; a control circuit mounted in the case of the appliance and configured to control the operation unit to perform appliance functionality that is different than measuring power; and a power meter coupled to the control circuit, built into the case, and configured to measure power consumed by the appliance in performing the appliance functionality, wherein the control circuit comprises: a microcomputer that is configured to control the appliance; a rectifier that is configured to rectify alternating current power received from the external power supply; a transformer that is configured to lower voltage of rectified alternating current power that is be provided to the microcomputer; and a rectifier circuit that is connected to the transformer and that is configured to rectify power outputted by the transformer, the power meter comprises: an electric power calculation circuit that is configured to calculate an amount of power provided by the external power supply, that is configured to provide the calculated amount of power to the control circuit, that is connected to the rectified circuit, and that receives the rectified power from the rectified circuit; a voltage-current measuring unit connected to the external power supply and configured to measure voltage and current supplied by the external power supply; the electric power calculation unit is configured to calculate an amount of power based on the voltage and current measured by the voltage-current measuring unit; the control circuit comprises: a first regulator configured to regulate voltage of the direct current power lowered by the transformer; and the power meter further comprises a second regulator connected between the rectifier circuit and the electric power calculation circuit and configured to lower voltage of the power rectified by the rectifier circuit. an operation unit that is mounted in a case of the appliance and being supplied with alternating current power by an external power supply, the operating unit including at least one of a motor and a heating member; a control circuit mounted in the case of the appliance and configured to control the operation unit to perform appliance functionality that is different than measuring power; and a power meter coupled to the control circuit, built into the case, and configured to measure power consumed by the appliance in performing the appliance functionality, wherein the control circuit comprises: a microcomputer that is configured to control the appliance; a rectifier that is configured to rectify alternating current power received from the external power supply; a transformer that is configured to lower voltage of rectified alternating current power that is be provided to the microcomputer; and a rectifier circuit that is connected to the transformer and that is configured to rectify power outputted by the transformer, a microcomputer that is configured to control the appliance; a rectifier that is configured to rectify alternating current power received from the external power supply; a transformer that is configured to lower voltage of rectified alternating current power that is be provided to the microcomputer; and a rectifier circuit that is connected to the transformer and that is configured to rectify power outputted by the transformer, the power meter comprises: an electric power calculation circuit that is configured to calculate an amount of power provided by the external power supply, that is configured to provide the calculated amount of power to the control circuit, that is connected to the rectified circuit, and that receives the rectified power from the rectified circuit; a voltage-current measuring unit connected to the external power supply and configured to measure voltage and current supplied by the external power supply; the electric power calculation unit is configured to calculate an amount of power based on the voltage and current measured by the voltage-current measuring unit; an electric power calculation circuit that is configured to calculate an amount of power provided by the external power supply, that is configured to provide the calculated amount of power to the control circuit, that is connected to the rectified circuit, and that receives the rectified power from the rectified circuit; a voltage-current measuring unit connected to the external power supply and configured to measure voltage and current supplied by the external power supply; the electric power calculation unit is configured to calculate an amount of power based on the voltage and current measured by the voltage-current measuring unit; the control circuit comprises: a first regulator configured to regulate voltage of the direct current power lowered by the transformer; and the power meter further comprises a second regulator connected between the rectifier circuit and the electric power calculation circuit and configured to lower voltage of the power rectified by the rectifier circuit. a first regulator configured to regulate voltage of the direct current power lowered by the transformer; and the power meter further comprises a second regulator connected between the rectifier circuit and the electric power calculation circuit and configured to lower voltage of the power rectified by the rectifier circuit.