The invention relates to an aircraft opening window comprising at least one pane (2) equipped with a movable frame (3), the assembly comprising the said movable frame (3) and the said at least one pane (2) being movable relative to a fixed frame (1), an element (4) for maneuvering the said movable assembly, a device for locking/unlocking and opening/closing the said movable assembly actuated by the said maneuvering element (4) and means for guiding and supporting the said movable assembly. According to the invention, the said fixed frame (1) is provided with at least one housing (6, 7, 8) for receiving a part at least of a first lateral rim (5) of the said movable frame (3), the said part at least of the said first lateral rim (5) becoming braced in the said at least one housing (6, 7, 8), by means of which housing or housings the said first lateral rim is held in place when the window is in closed position, and the said part at least of the first lateral rim being received in the said housing (6, 7, 8), the said guiding means of the said movable assembly permits rotation of the said assembly around an axis of rotation (11) passing through the first lateral rim (5) so as to place the other lateral rim of the said movable frame (3) in closed or released position.