To make amounts of business loads of medical workers become equal when a call from a patient is performed and portable terminals held by a plurality medical workers who take charge of the patient are called in order.

Since an order for calling the portable terminals 30 to the call from a nurse call slave unit 1 is stored in a storage part 13, the number of steps of the medical workers who carry the portable terminals 30 is counted with a pedometer 40, and an order that a portable terminal carried by a medical worker whose number of steps is less value is advanced, priority is given to the call to the portable terminal 30 carried by the medical worker whose number of steps is less, a call to a medical worker whose number of steps decreases more, and a call to the medical worker whose number of steps increases less. Consequently, when the medical worker whose number of step is less responds to the call by the nurse call slave unit 1, the number of steps of the medical worker increases. Thus, physical activities of the medical workers are equalized and the amounts of business loads of the medical workers are equalized as much as possible.