  A vector-like extension of the standard model for heavier quarks and leptons
with $SU(2)\times U(1)$ gauge symmetry and only one Higgs doublet is examined.
This scheme incorporates infinitely many fermions and avoids the appearance of
a strongly interacting sector. The model is perturbatively well controllable,
and constraints such as $b\rightarrow s\gamma$ and GIM suppression in general
are naturally satisfied if the on-set of heavier fermion mass scale is chosen
at a few TeV. In this scheme, the physical Higgs particle generally mediates
leptonic as well as quark flavor-changing processes at a rate below the present
experimental limit. Vector-like models, if suitably defined, provide a viable
and interesting scheme for physics beyond 1 TeV.
