A converter capable of suppressing an instant voltage variation and outputting a desired DC power with high precision. The converter includes a power conversion unit that conducts power conversion on a supplied power, a smoothing filter that smoothes the power that has been converted in power, a voltage detector that detects a voltage of the smoothed power, and control unit that outputs a pulse signal for controlling a conduction ratio of a switching element within the power conversion unit so that an output voltage from the voltage detector becomes a desired voltage value. The control unit temporarily stops the power supply when the output voltage increases up to a first given voltage and restarts the power supply when the output voltage decreases down to a second given voltage.