PURPOSE: To enable an image display unit for monitoring the operating condition of a vehicle to recognize any abnormality, retrieve information about the abnormality in accordance with a driver's instructions, and either interrupt an image being displayed with the information or switch images.

CONSTITUTION: An image display unit is constructed mainly of microcomputers, and receives signal inputs from a navigation system that stores operating data about vehicle speed, the distance covered, parking and the like and from a TV broadcasting system, and causes images displayed on its monitor to be switched in accordance with a driver's instructions transmitted via a control portion. A means 21 for monitoring the operating condition of the vehicle receives signal inputs from a variety of sensors for vehicle speed, engine speed, an ignition switch, braking pressure, brake fluid leaks, the amount of wear of a pad, the use of a seat belt, and the like, and recognizes 22 any abnormality by comparing the inputs with reference values, and, in the event of an abnormality, retrieves 23 information about the abnormality, and interrupts 24 an image being displayed with the information retrieved.