PURPOSE: To prevent a trouble that a burglar warning switch is undesirably turned on and warning is executed by providing a display means to display the opening condition of a window or a door.

CONSTITUTION: A warning means is provided to detect the opening and closing condition of the window or the door and to execute the warning and the burglar warning switch is provided to switch the turning-on and off of this warning means. Then, the display means is equipped to display the opening condition of the window or the door. Thus, since the opening condition of the window or the door is displayed, the trouble that the burglar warning is turned on and the warning is undesirably executed even when the window is opened is eliminated. Accordingly, it can be prevented that announcement is transmitted even to a carataker room by erroneous use and goes to be a trouble.