  We propose a renormalizable model of a fermionic dark matter by introducing a
gauge singlet Dirac fermion and a real singlet scalar. The bridges between the
singlet sector and the standard model sector are only the singlet scalar
interaction terms with the standard model Higgs field. The singlet fermion
couples to the standard model particles through the mixing between the standard
model Higgs and singlet scalar and is naturally a weakly interacting massive
particle (WIMP). The measured relic abundance can be explained by the singlet
fermionic dark matter as the WIMP within this model. Collider implication of
the singlet fermionic dark matter is also discussed. Predicted is the elastic
scattering cross section of the singlet fermion into target nuclei for a direct
detection of the dark matter. Search of the direct detection of the dark matter
provides severe constraints on the parameters of our model.
