To provide a nurse call system for informing a nurse of a call from a patient without depending on specific calling operation using a call button.

A master unit is informed of a call from a slave unit 2a by a patient as an acceleration sensor 12 provided in a call button senses that the patient drops the call button 1a. When the patient drops the call button, wired connection between the call button and the slave unit is disconnected if, for example, the call button is pulled out of the slave unit with the dropping. When the disconnected state is detected by a disconnection detection circuit 22 in the slave unit, the master unit is informed of an emergency call from the slave unit by the patient.