An ECU executes a program including the steps of: setting a target boost voltage to a maximum value when a request for changing a sub power supply is made; temporarily increasing discharge electric power of a main power supply and then restricting discharge electric power of the sub power supply before switching; shutting off a gate of a converter on the sub power supply side; performing processing for shutting off an SMR corresponding to the sub power supply before switching; connecting an SMR corresponding to a sub power supply after switching when an absolute value of a current is equal to or lower than a predetermined value; canceling shut-off of the gate of the converter on the sub power supply side; canceling temporary increase in discharge electric power of the main power supply and restriction of discharge electric power of the sub power supply; and canceling the setting of the maximum value as the target boost voltage.