To provide a primary battery charger having a simple structure which can be manufactured at low cost.

The primary battery charger comprises a USB interface 22c performing serial data communication with a computer terminal 10 connected via a USB cable 6; battery sockets 25a and 25b, to which primary batteries 30a and 30b can be attached, charging circuit sections 29a and 29b for charging the primary batteries 30a and 30b by applying a charging voltage, based on a DC power supplied from the computer terminal 10 via the USB cable 6; and a means 22 for transmitting the charging information data, which is required to display information about charging on the computer terminal 10, through the USB interface 22c.