PURPOSE: To improve serviceability by informing reservation contents which conference room is filled at which point, and making another reservation easy to be taken by changing the content of reservation by a user.

CONSTITUTION: In the case of reserving the conference room X at a point A and the conference room Y at a point B for a time zone T, the user inputs the contents of reservation to a terminal 1. And a controller 23 indicates a line retriever 20 to retrieve the state of a line between the points A and B and the state of vacancy/filling out of the contents of reservation. When it is vacant, the conference room X at the point A is retrieved. Also, when the line is not vacant, the controller 23 starts up a reply device 22. The device 22 replies another time zone when a designated time zone is filled and another time zone is acceptable. When the user inputs an answer NO to the terminal 1, the controller 23 performs completion processing. Also, when the user inputs another time zone, the retriever 20 inspects the line at that time zone. Next, the conference room Y at the point B is inspected when the conference room X at the point A is filled.