To solve such a problem that accuracy of abnormality detection in a server is degraded when an update of its configuration is taken into consideration.

A management server comprises: server configuration storage means which is connected with a plurality of servers comprising means for recording start and end time of system initialization, and stores configurations of the respective servers; server selection means which selects servers whose configurations are considered to be identical by referring to the server configuration storage means; abnormality determination means which compares initialization times acquired from start and end time of system initialization of the selected respective servers, and determines that there is abnormality in a server when difference between the maximum and the minimum initialization time is equal to or greater than a predetermined value; and abnormality notification means for giving notification of abnormality on the basis of determination by the abnormality determination means.