In an awning having a substantially triangular awning fabric that can be wound onto a roller tube, provision is made for the roller tube to be actuated in the winding direction by a torsion spring that is disposed in a housing together with the roller tube; for the roller tube to be actuated in the pull-out direction by an electric motor that is disposed in the same housing; for a guide rail to be disposed on one end of the housing and a spacer rail to be disposed on the other end of the housing, said guide rail and spacer rail being connected in the region of their free outer ends to one another or to a window frame; for a deflection roller to be disposed in the connecting region of the spacer rail and guide rail; and for a rope or the like to be attached in the region of the triangular cloth tip and deflected via the deflection roller and guided along the guide rail to a rope sheave on the motor.