The structural stability and energetics of carbon, silicon, and germanium microclusters containing 3-7 atoms have been investigated by using a recently developed empirical many-body potential energy function (PEF), which comprises two- and three-body atomic interactions. The PEF satisfies both bulk cohesive energy per atom and bulk stability exactly. It has been found that the most stable C3-4 microclusters are linear with D-infinity-h symmetry but C5-7 microclusters are planar with D(nh) symmetry. Silicon and germanium microclusters show similar structural stability. The X(n)(X = Si, Ge; n = 3-7) microclusters are found to be most stable in the following forms: X3 is triangular with D3h symmetry, X4 is tetragonal with T(d) symmetry, X5 is square pyramidal with D4h symmetry, X6 is bipyramidal square with O(h) symmetry, and finally X7 is square pyramidal having two atoms underneath with D2h symmetry.