We study D = 4, N = 1, type IIA orientifold with orbifold group ZN and ZN × ZM . We calculate one-loop vacuum amplitudes for Klein bottle, cylinder and Möbius strip and extract the tadpole divergences. We find that the tadpole cancellation conditions thus obtained are satisfied by the Z4, Z8, Z ′ 8, Z ′ 12 orientifolds while there is no solution for Z3, Z7, Z6, Z ′ 6, Z12. The Z4 × Z4 type IIA ...