PURPOSE: To prevent the occurrence of a human error such as the oversight of the display of abnormality, etc., and to attain labor-saving by displaying visually data obtained by a visual operation data accumating, displaying or controlling function, and monitoring the operation of plural host computers connected with each other by a communication line from a terminal installed at a distant place.

CONSTITUTION: A job processing executing state monitoring function 4 monitors the executing state of an application program intrinsic to job processing in plural computers, and displays visually this result on the terminal installed at the distant place. A plural computers operation data accumulating, displaying or controlling function 5 accumulates the filtered result of the data obtained by a faulty data transferring state monitoring function 1, a plural computers life-and-death monitoring function 2, a job processing sorting state monitoring function 3 and the job processing executing state monitor function 4 as operation data, and outputs the operation data after processing it in conformity to a request from an output function 7.