Abstract: A side-hinged, 180 degrees rotatable window, having a window casement which is pivotably mounted about a first vertical axis and about a second vertical axis relative to a window frame. The window casement is supported hanging at its one upper corner via a head portion (27) on a pivot pin (26) in a carriage (25), which is displaceable in a horizontal guide (16) in the window frame. The window casement is pivotably mounted at its center axis at the one end of an upper and a lower support or pivot arm, the opposite end of which is pivotably mounted about a third vertical axis in the window frame. The carriage (25) is designed with a part-spherical seat (25') for an equivalent part spherical portion of the support head (27) of the first pivot pin.