PURPOSE: To take a speedy and proper countermeasure for abnormality by extracting, displaying, printing, and voicing corresponding indication information according to the cause of the abnormality estimated corresponding to the cause of abnormality which occurs to a plant.

CONSTITUTION: An abnormality cause estimating means 12 estimates the cause of the abnormality of the plant and informs an abnormality display information extracting means 13 of the result. The abnormality display information extracting means 13 extracts the corresponding abnormality display information from plural pieces of abnormality display information set corresponding to the cause of abnormality which possibly occurs to the plant according to the estimated cause of the abnormality and outputs it to a display means 14. Further, corresponding indication information is extracted according to the estimated cause of the abnormality and outputted to a display means 14, a printing means 16, and a voice output means 18 respectively. Consequently, the contents of the occurring abnormality and a way of handling it can be grasped at a glance and the speedy and proper countermeasure is taken.