  Diffractive events are studied by means of identification of one or more
rapidity gaps and/or a leading antiproton. Measurements of soft and hard
diffractive processes have been performed at the Tevatron $p\bar p$ collider
and presented. We report on the diffractive structure function obtained from
dijet production in the range $0<Q^2<10,000$GeV$^2$, and on the $|t|$
distribution in the region $0<|t|<1$GeV$^2$ for both soft and hard diffractive
events up to $Q^2\approx 4,500$GeV$^2$. Results on single diffractive W/Z
production, forward jets, and central exclusive production of both dijets and
Z-bosons are also presented.
