A booster comprising: a booster circuit arranged to receive either one of start-up energy necessary for starting up the booster circuit and operation energy necessary for continuing an operation of the booster circuit, wherein the booster circuit is arranged to generate a boosted output obtained by boosting an input voltage as a target to be boosted, wherein the booster circuit feeds back all or a part of the boosted output to the booster circuit itself as the operation energy, characterized by the booster circuit further comprising: an auxiliary booster circuit arranged to output the start-up energy generated based on the input voltage input to the booster circuit; a voltage judging unit (82a, 82b) arranged to judge whether an output voltage of an auxiliary booster circuit output that is an output of the auxiliary booster circuit exceeds a predetermined voltage, wherein the voltage judging unit (82a, 82b) includes a capacitor (86, 90) arranged to store the output of the auxiliary booster circuit at the output voltage, and wherein the predetermined voltage is set so that, when the output voltage exceeds the predetermined voltage, the amount of energy stored in the capacitor (86, 90) has reached an amount of energy that allows start-up of the booster circuit; and a switching unit (83a, 83b) arranged to switch supply/stop of the auxiliary booster circuit output to the booster circuit based on a result of judgment by the voltage judging unit (82a, 82b), such that, when the voltage judging unit (82a, 82b) judges that the output voltage exceeds the predetermined voltage, the output of the auxiliary booster circuit is supplied to the booster circuit. a booster circuit arranged to receive either one of start-up energy necessary for starting up the booster circuit and operation energy necessary for continuing an operation of the booster circuit, wherein the booster circuit is arranged to generate a boosted output obtained by boosting an input voltage as a target to be boosted, wherein the booster circuit feeds back all or a part of the boosted output to the booster circuit itself as the operation energy, characterized by the booster circuit further comprising: an auxiliary booster circuit arranged to output the start-up energy generated based on the input voltage input to the booster circuit; a voltage judging unit (82a, 82b) arranged to judge whether an output voltage of an auxiliary booster circuit output that is an output of the auxiliary booster circuit exceeds a predetermined voltage, wherein the voltage judging unit (82a, 82b) includes a capacitor (86, 90) arranged to store the output of the auxiliary booster circuit at the output voltage, and wherein the predetermined voltage is set so that, when the output voltage exceeds the predetermined voltage, the amount of energy stored in the capacitor (86, 90) has reached an amount of energy that allows start-up of the booster circuit; and a switching unit (83a, 83b) arranged to switch supply/stop of the auxiliary booster circuit output to the booster circuit based on a result of judgment by the voltage judging unit (82a, 82b), such that, when the voltage judging unit (82a, 82b) judges that the output voltage exceeds the predetermined voltage, the output of the auxiliary booster circuit is supplied to the booster circuit. an auxiliary booster circuit arranged to output the start-up energy generated based on the input voltage input to the booster circuit; a voltage judging unit (82a, 82b) arranged to judge whether an output voltage of an auxiliary booster circuit output that is an output of the auxiliary booster circuit exceeds a predetermined voltage, wherein the voltage judging unit (82a, 82b) includes a capacitor (86, 90) arranged to store the output of the auxiliary booster circuit at the output voltage, and wherein the predetermined voltage is set so that, when the output voltage exceeds the predetermined voltage, the amount of energy stored in the capacitor (86, 90) has reached an amount of energy that allows start-up of the booster circuit; and a switching unit (83a, 83b) arranged to switch supply/stop of the auxiliary booster circuit output to the booster circuit based on a result of judgment by the voltage judging unit (82a, 82b), such that, when the voltage judging unit (82a, 82b) judges that the output voltage exceeds the predetermined voltage, the output of the auxiliary booster circuit is supplied to the booster circuit.