Plant alarm apparatus and plant alarm method

The present invention relates to a plant alarm apparatus and plant alarm method, for detecting the symptom of plant exception and notifying operator in advance. The plant alarm apparatus includes alarm-triggering value alteration means (6) for updating the points for detecting plant abnormality in an alarm-triggering value registration table (8) in response to a request by an operator; alarm-triggering condition editing means (7) for registering alarm-triggering conditions of points showing a foretoken of abnormality; deviation-from-limit-value determining means (10) for reading the stored values of the alarm-triggering value registration table (8) and the alarm-triggering condition table (9) and comparing the limit values of the points for detecting abnormality; and alarm notification output means (12) for outputting the outcome of the comparison to a display device (13), when the result of the deviation-from-limit-value determining means (10) is beyond a prescribed range.