PROBLEM TO BE SOLVED: To appropriately put on hold a coming-off call when a nurse call slave machine comes off from a wall unit, without providing a button for putting the calling-off call on hold.SOLUTION: A wall unit 10 comprises: a cover 15 that transfers between a first state where the cover forms a substantially same plane as a wall surface and a second state where the cover projects from the wall surface to form a hook for hanging a ring of a nurse call slave machin 1 and an outlet 12 that is covered when the cover 15 is transferred from the second state to the first state and detachably connected to a plug 4 of the nurse call slave machine 1. When the cover 15 transfers to the first state until a prescribed time elapses after the plug 4 has come off from the outlet 12, the nurse call system does not perform a notification of the coming-off call, however, when the cover 15 is in the second state after the lapse of the prescribed time, performs the notification of the coming-off call. Therefore, when the plug is intentionally removed, no coming-off call is performed by natural movement when the cover 15 is stored.
