To reliably detect a crack of window glass by setting the window glass at a part for detecting the crack of the glass from a cracked state to a scattered state when the window glass is broken.

The non-opening/closing type window glass 13 is constituted of a glass sheet which is wholly cracked when a part thereof is broken. The window glass 13 is fixed to a body 15 at its peripheral edge with an adhesive 14. A leaf spring 16 is provided at the body 15 at a part corresponding to the circumferential edge of the window glass 13. The leaf spring 16 is provided so that pressure capable of breaking a part of the window glass 13 when the window glass 13 is cracked is applied to the window glass 13. A micro switch 17 is fixed to the body 15 to a part of the body 16 corresponding to the part to be broken by the action of the leaf spring 16 so that the movement of an actuator 18 to a projecting side is regulated by the window glass 13.