The direct scanning tunneling microscopy (STM) imaging of the isolated discandium fullerenes (Sc-2@C-84) on silicon clean surfaces in an ultrahigh-vacuum environment has been reported for the first time. The STM images reveal nearly spherical Sc-2@C-84 fullerenes, spaced 11.7 Angstrom apart and stacked in close-packed arrays at room temperature. The results present the first direct evidence that the scandium atoms are trapped inside the C-84 cage.