A menu screen display method for an in-car information system comprising an information terminal and an in-car device that is connected to the information terminal to communicate with the information terminal, the in-car device includes: a display monitor of a touch panel type; an interface unit that transmits actuation information on the basis of actuation on the display monitor to the information terminal; a video signal input unit that receives a video signal transmitted from the information terminal; and a control unit; and wherein the information terminal includes: an information terminal display monitor of a touch panel type; an information terminal interface unit that is configured to receive the actuation information; a video signal output unit that is configured to transmit the video signal for a display on the in-car device display monitor; and a memory unit that is configured to store an application for the in-car information system capable to be selected and started via the actuation on the in-car device display monitor and an application manager that is configured to recognize the application for the in-car information system selected via the actuation on the in-car device display monitor; characterized in that the menu screen display method comprises: setting the control unit of the in-car device to transmit a start command for the application manager stored in the information terminal from the in-car device to the information terminal when the control unit has decided that both the interface unit and the video signal input unit are connected to the information terminal; configuring the information terminal to start the application manager to transmit, from the video signal output unit to the in car device, the video signal for displaying a menu screen on the in car device display monitor when the information terminal receives the start command from the in car device; receiving the video signal for displaying the menu screen by the video signal input unit from the information terminal; and displaying the menu screen on the display monitor on the basis of the received video signal. a display monitor of a touch panel type; an interface unit that transmits actuation information on the basis of actuation on the display monitor to the information terminal; a video signal input unit that receives a video signal transmitted from the information terminal; and a control unit; and an information terminal display monitor of a touch panel type; an information terminal interface unit that is configured to receive the actuation information; a video signal output unit that is configured to transmit the video signal for a display on the in-car device display monitor; and a memory unit that is configured to store an application for the in-car information system capable to be selected and started via the actuation on the in-car device display monitor and an application manager that is configured to recognize the application for the in-car information system selected via the actuation on the in-car device display monitor; characterized in that setting the control unit of the in-car device to transmit a start command for the application manager stored in the information terminal from the in-car device to the information terminal when the control unit has decided that both the interface unit and the video signal input unit are connected to the information terminal; configuring the information terminal to start the application manager to transmit, from the video signal output unit to the in car device, the video signal for displaying a menu screen on the in car device display monitor when the information terminal receives the start command from the in car device; receiving the video signal for displaying the menu screen by the video signal input unit from the information terminal; and displaying the menu screen on the display monitor on the basis of the received video signal.