To present a proper operation instruction to a serviceman who maintains an image forming device.

This image forming device managing apparatus which manages operation states of a plurality of image forming devices through a communication line is equipped with: a means of generating reception records of error information among various state data sent from the respective image forming devices as current machine type history information; and a cause analyzing means of analyzing the cause of a specific error by using last machine type history information regarding error occurrence of a device installed before a current machine type is installed, the current machine type history information generated by the history information generating means, and the last machine type history information and gives an operation instruction including whether device has a problem characteristic of the new machine type or a user side to the service man who maintains the image forming device.