PURPOSE: To improve operability for monitoring, by expressing many management data by a series of a plurality of display pictures, and automatically switching the picture to the next picture.

CONSTITUTION: A processing device 701 receives the data required for the operation monitoring and management of a plant from a plant process 1 through an input device 2 and stores the data in a group of memory devices 702-1W702-l. Thereafter, the data is read out, processed, and edited. A plurality of display data suitable for CRT4 are prepared and stored into the memory devices again. When a series of the display data is specified by a request device 8 and the display of the pictures is requested, the applicable group of the display pictures 9 is sequentially displayed on the CRT4 with a constant time interval. The picture is automatically changed to the next picture at a speed corresponding to the purpose. The operator observes the display picture, stops the display, and produces a copy by a recording device 10.