The present invention provides a technology of detecting reconnection of a storage battery even though an ignition switch is in OFF state. A vehicle-mounted device control apparatus comprises an IG detection unit, a connection detecting unit, and a control unit, wherein the IG detection unit detects that the ignition switch is turned on or off; the connection detecting unit outputs a drive signal for driving a relay connected to the storage battery when the battery is detected in connection; and the control unit is started when providing power by the relay, the relay after being started judges on and off of the ignition switch, and when the ignition switch is off, the determination is that the battery is connected.