A vehicle information provision device comprising: an on-board device including a device unit including a display unit that displays various states of a vehicle as vehicle status information to the user and a first control means that operates the display unit ; and a communications unit that communicates between the device unit and an external device that outputs external information for the vehicle to the device unit , wherein the communications unit is configured to be connectable to the device unit through attachment/detachment means , and outputs the external information for the vehicle to the device unit , when the device unit is connected to the communications unit through the attachment/detachment means , wherein the display unit has a first display region (R1) displaying a predetermined type of information (D1) out of the vehicle status information and a second display region (R2) displaying another type of information (D2) out of the vehicle status information, which is different from the predetermined type of information (D1), the vehicle information is characterised in that when the first control means is connected to the communications unit through the attachment/detachment means , the first control means executes a first display mode (M1) for displaying the vehicle status information on the display unit and a second display mode (M2) for displaying the vehicle status information and the external information for the vehicle on the display unit , and in the second display mode (M2), the first control means operates the display unit so as to display the external information for the vehicle in the second display region (R2), in that the first display region (R1) is configured as a fixed display region in which the predetermined types of information (D1) are displayed in predetermined display positions, regardless of the display mode (M1, M2), and in that the second display region (R2) is configured as a variable display region and the first control means controls the display layout of the second display region (R2). wherein the display unit has a first display region (R1) displaying a predetermined type of information (D1) out of the vehicle status information and a second display region (R2) displaying another type of information (D2) out of the vehicle status information, which is different from the predetermined type of information (D1), the vehicle information is characterised in that when the first control means is connected to the communications unit through the attachment/detachment means , the first control means executes a first display mode (M1) for displaying the vehicle status information on the display unit and a second display mode (M2) for displaying the vehicle status information and the external information for the vehicle on the display unit , and in the second display mode (M2), the first control means operates the display unit so as to display the external information for the vehicle in the second display region (R2), in that the first display region (R1) is configured as a fixed display region in which the predetermined types of information (D1) are displayed in predetermined display positions, regardless of the display mode (M1, M2), and in that the second display region (R2) is configured as a variable display region and the first control means controls the display layout of the second display region (R2). <EOS>