PURPOSE: To collect alarm information more quickly in the alarm collection system collecting periodically the alarm information and processing the information.

CONSTITUTION: Buffers 11, 12 sending alarm information from plural units in a timing predetermined by its own unit in one collection cycle are provided to a monitor controller 10. The alarm information sent during one collection cycle from each unit is written to either of the buffers 11, 12. The alarm information is read from a buffer to which no alarm information is written in both the buffers. A processing section 14 selects the buffers 11, 12 for each one collection cycle to process the read alarm information. Since it is not required to make polling from the monitor controller 10, the alarm information is quickly collected.