  Supersymmetric orientifolds of four dimensional Gepner Models are constructed
in a systematic way. For all levels of the Gepner model being odd the generic
expression for both the A-type and the B-type Klein bottle amplitude is
derived. The appearing massless tadpoles are canceled by introducing
appropriate boundary states of Recknagel/Schomerus(RS). After determining the
Moebius strip amplitude we extract general expressions for the tadpole
cancellation conditions. We discuss the issue of chirality for such
supersymmetric orientifold models and finally present a couple of examples in
detail.
