The ternary metallic glass Zr65.0Al7.5Cu27.5 shows a wide supercooled liquid region above the glass transition temperature T-g, which enables extended structural investigations of the undercooled Liquid. Thin films of this alloy have been prepared by electron beam deposition in ultra high vacuum onto thermally oxidized silicon substrates at room temperature. For the first time the surface morphology of these films has been investigated in situ with scanning tunnelling microscopy (STM). We have recorded STM topographs after different annealing stages, representing the evolution of the surface at elevated temperatures. The change in surface structure is discussed with respect to structural relaxation behaviour and viscous flow properties of the films.