Abstract: The present invention refers to a mechanism for the opening and for the shutting of a window, particularly designed for use in the emergency windows of a public transportation vehicle provided with a lower release and locking window (1) system and another upper system that allows for the scaling when opening it, considering the fact that the lower system is actuated by means of a lever (5) that extends along the lower extremity of the window (1), which allows for its actuation by any passenger positioned in its proximity.