To improve a gateway device for minimizing the battery consumption while coping with a particular situation which is considered to seldom occurs.

When the transmission of the present position data is requested from a monitoring center 100 and the like, for example, in a case when a stolen car is abandoned, the gateway device 1 receives the request, and turns an ACC switch 5 on through an ACC relay 7. Whereby the power is fed to an ECU connected to an information system LAN from a battery 3, and the gateway device 1 gives a command to detect the present position to the navigation ECU 10. The navigation ECU 10 receiving the command for detection acquires the GPS data through a GPS receiver 13, and transmits the present position data specified on the basis of the GPS data to the gateway device 1. The gateway device 1 acquires the present position data, and transmits the same to a requester.