Antitheft window

The utility model provides an antitheft window which relates to a window for ventilation and daylighting for a building. The antitheft window is composed of a window frame, a window sash and a locking mechanism, and is characterized in that the window frame is formed by an outer frame and an inner frame connected with the outer frame and capable of opening and closing in relative to the outer frame. The inner frame is fixedly provided with a parapet, and the window sash is positioned on the inner frame. When the inner frame is closed, the parapet fixed on the inner frame can prevent a thief from illegally entering, serving antitheft function; when in a fire disaster or other accidental situations, the inner frame is opened to form a passage for people to access, satisfying the fire-fighting requirements. The utility model, which has complete functions and flexible and convenient operation, can substitute the prior window.