A charging control circuit according to an embodiment of the present invention includes a detecting circuit and a charging transistor control unit for controlling a charging transistor supplying a first current, a current source for supplying a second current, and a current source control unit for controlling the current source. For example, if a secondary battery is charged using an adaptor endowed with a current-limiting function, during a constant-current charging period in which a charging voltage of the secondary battery reaches 3.2 V to 4.2 V, the secondary battery is charged with the first current I1, and during a constant-voltage charging period after the voltage reaches 4.2 V, the secondary battery is charged with the first charging current and the second charging current.