A mobile device is provided. The mobile device provides simple connection with a mobile device unit, resistant to noise from the mobile device unit, and enabling a GPS function to be fully exhibited, wherein a first integrated circuit IC21 mounting a GPS receiver and GPS antenna and a second integrated circuit IC22 mounting a controller control circuit are housed in a controller unit, the controller unit is provided with a headphone jack and a music/speech terminal-GPS terminal to be connected to the mobile device unit, and the terminal is inserted into the mobile device unit to supply power source voltage from the mobile device unit side and enable the controller and GPS function to be used.