A remote maintenance system has a monitoring computer for monitoring a facility and a monitoring center computer for maintenance management. The monitoring computer has a database for storing image data of the monitored facility. The monitoring center computer a database for storing CAD data for the monitored facility. The monitoring center computer provides coordinates to the image data sent from the monitoring computer, and superposes the image coordinate data and CAD coordinate data for the CAD. The center computer locates a needed maintenance location on the basis of the result of the superposition processing.