In nurse call systems that enable communication from a plurality of cordless handsets with a plurality of extension terminals carried by nurses belonging to a group, a nurse call conversion unit is provided between a nurse call control device and a private branch exchange. A call signal for a group representative call in which only an identification number for a group is given is transmitted by the nurse call conversion unit from the nurse call control device to the private branch exchange. From this call signal, the private branch exchange generates a call signal for extension terminals belonging to a group and calls the extension terminals.