PURPOSE: To specify a defect position by diagnosing through a diagnosing interface to the equivalent part of a defect processing device, and localizing the defect position of the equivalent part when it is judged as the application of a log analyzing means that the defect position cannot be localized.

CONSTITUTION: Assuming that a defect is generated at a part B1 of a processing device 1, the generated log information is assumed as LB1. After a log analyzing means 30 started from a log collecting means 20 identifies a processing device, the log information defined for respective processing devices judges whether or not the generated log information comes to be the object of a log analysis. Log information LB1 is judged to be except the log analyzing object and delivers a processing device name=processing device 1 and log information=LB1 to a diagnosing executing control means 50. A diagnosing executing control means 50 searches and executes the diagnosing to B1 corresponding to the log information LB1 in a diagnosing executing means 60 of the processing device 1 from a processing device name, and when an error is detected, the defect position is made local by the type of the error. Thus, the localizing capacity to point out the defect position is improved.