The present invention is related to a control method for controlling a power converter including a first power conversion circuit 11 and a second power conversion circuit 12 by using a control circuit 13. The first power conversion circuit 11 is connected to a solar cell module 1 and a capacitor 2, converts output power of the solar cell module 1, and outputs the converted power to the capacitor 2, the second power conversion circuit 12 is connected to the capacitor 2, and converts a voltage at a connection terminal connected to the capacitor 2. The control method comprises step of controlling operation of the second power conversion circuit 12 based on the output voltage of the solar cell module 1, to use output power of the second power conversion circuit 12 for charging the capacitor 2.