A charge control circuit comprises: a first/second comparator circuit configured to compare a voltage of a secondary battery with a first/second comparison voltage; a first transistor configured to supply an input current to an inductor of a boost DC-DC converter; a first control circuit configured to control the first transistor; and a second control circuit configured to cause the boost DC-DC converter to perform the boost operation. The first transistor is configured to be turned on, and the switching of the second/third transistor to increase/decrease the inductor current is performed in a complementary manner, and the boost DC-DC converter is caused to perform the boost operation, when the voltage of the secondary battery is equal to or higher than the first comparison voltage. The gradient of a ramp wave compared with an error signal is steepened, when the voltage of the secondary battery is lower than a second comparison voltage. The first transistor is controlled so that the input current takes a predetermined value, and the second transistor is turned off and the third transistor is turned on, when the voltage of the secondary battery is lower than the first comparison voltage. Thus, a voltage for charging the secondary battery having a full charge voltage higher than the input voltage is obtained.