A voltage control circuit includes a voltage step-up device that steps up an applied voltage to a stepped-up voltage, an electronic device to which the stepped-up voltage is applied, a current monitor that monitors a supplied current that is supplied to the electronic device, based on the stepped-up voltage, a step-up controller that controls the stepped-up voltage to be a predetermined target voltage, based on the supplied current, and a warning provider that provides a warning when the current monitor can not monitor the supplied current.