PURPOSE: To shorten the occupation time of a public line and confirm data history by extracting a data group by plural sampling times stored in a memory in the lump through the public line.

CONSTITUTION: A data storage means 5 of a controller 1 samples operator data of a refrigerator 10 extracted via an input device 51 for a predetermined time counted by a timer 50, e.g. elapse of 1 hour and stores the result to a memory 4. Furthermore, a data extract means 6 provides an output the data group by plural samplings stored in the memory 4 via an output device 61 to a public line 3 when a count of a counter 60 integrating number of sampling times reaches, e.g. 24, that is, a day elapses. Thus, the operation data of the refrigerator are sampled for each hour and stored in the memory 4 and the sampling data group for 24 hours is sent to the public line 3 in the lump when a day elapses.