PURPOSE: To improve the convenience of use by a user in the case of operating a device by displaying an operation guidance with respect to an object of a noted display window onto an operation guidance display window when the operation to the noted display window is a mis-operation.

CONSTITUTION: An operation sequence management section SEQ, a multi-window management section MWN, a multi-window display section MWA and an operation guidance management section GWM apply properly display data to an input output management section SPM. Furthermore, input data from a touch pulse device 2b and a touch pen 3 are respectively outputted to a processing means managing the display of a noted display window. A system program monitors whether or not the user conducts any operation to the noted display window within a specified time stored in a window output table file. When the content of the operation made by the user is not normal, display of an operation guidance is requested and display processing to guide a proper operation content with respect to the object operation is executed.