To allow a person other than a patient in a hospital room to perform a call even without carrying a radio tag by raising the emergency degree of the call while reducing the emergency degree of a call for a patient having such a problem that the patient immoderately operates a nurse call slave set arranged in the hospital room.

The priority order of the call from the nurse call slave set 1 is set to be low for the patient with the problem, and the number of persons using beds corresponding to the nurse call slave sets 1 is prestored for each hospital room. When the number of persons present in the hospital room, which is detected by a detection device S, is larger than the number of persons using the beds, it is determined that a person other than the patient is present in the hospital room, so that the priority order of the call is set to be high. When the number of persons present in the hospital room is equal to or less than the number of persons using the beds, it is determined that only the patients using the beds of the hospital room are present in the hospital room, so that the priority order of the call is kept to be set at a low level.