Abstract: An alarm system in a plant for outputting a plurality of alarms with respect to devices constituting the plant and monitor information with respect to the devices. In the system, there is provided a unit for storing a table for correspondingly relating a plurality of alarm items to suppression reason items indicating that the display of the alarms can be suppressed. A generated alarm item and a generated event are specified by receiving the plurality of alarms and monitor information. A decision is made by reference to the table as to whether the generated alarm suppression reason item exists in the monitor information, the kind of generated alarm, and the generated event for each generated alarm item. An instruction is given to a display unit to suppress the display of alarms in which a decision is made that the suppression reason item exists.