To reduce burden of a manager by giving a priority to information.

Various kinds of information 61 such as confirmation object information 61a to 61d, etc., acquired from a computer 60 and desired by an operator and various kinds of confirmation object information 31a to 31e stored by being weighted in advance and desired by the operator are compared. The confirmation object information desired by the operator is selected among the various kinds of information 61 from the computer 60. A prescribed weighting calculation is performed for the confirmation object information based on weight of the pertinent confirmation object information defined in advance. Based on the weighting arithmetic processing, the priority is given to the confirmation object information desired by the operator. Based on the result, the confirmation object information desired by the operator is displayed on a display means 70.