To display patient information of a patient who gave calling in an easily visible manner while personal information of patients other than the patient who gave calling is protected even when a plurality of patients in the same patient's room gave calling.

When calling is given through a plurality of nurse call sets installed according to number of bed in the patient's room, display areas a and b of patients who gave calling are sequentially displayed as enlarged areas A and B, and positions of the display areas a and b of the patients who gave calling are displayed, so that personal information of patients who did not give calling is masked and protected by the enlarged areas A and B. In addition, the display areas a and b can be enlarged, and patient information of patients who gave calling can be displayed in the easily visible manner. Consequently, medical staffs can easily see patient information of the patients who gave calling and can intuitively understand the positions of the patients.