To realize a method for maintenance which prevents equipment from getting out of order by speedily deciding a fault of an automatic teller machine.

Abnormality data detected in transaction processing of the automatic teller machine are classified and stored by parts of the equipment and the abnormality data accumulated in the operation of the automatic teller machine are compared by the parts with a threshold to decide the possibility of a fault; when it is decided that a fault will possibly occurs, the decision result is reported.