To provide a charger that enables safe and stable charging operation when a power supply for charging is switched.

The charger includes: a first power supply 111 having a current limiting function; a second power supply 112 lower in current limiting function than the first power supply 111; a first charging circuit 120 that charges a battery 101 with the first power supply 111; a second charging circuit 130 that charges the battery 101 with the second power supply 112; and a power supply selection circuit 140 that detects the voltage of the first power supply and the voltage of the second power supply, and controls the charging operation of the second charging circuit, based on the result of the detection. The first charging circuit 120 or the second charging circuit 130 is selected according to the output voltage of the first power supply 111 having the current limiting function. During the charging operation from the second power supply 112 lower in the current limiting function, the charging current is constantly controlled.