When a warning lamp 20a on the meter panel lights up in an in-vehicle system 1, the description of the content of warning and coping strategies about the lighted warning lamp are displayed on a display device 13. Thus, a user can be swiftly informed of the description of the content of warning and coping strategies. This can make it unnecessary for the user to spend time and effort looking for a service manual and opening the service manual and searching for appropriate pages, and can enhance user-friendliness.