This letter presents the design of a Ku-band cross-coupled order inductive post SIW ceramic filter, implemented with a novel cross-coupling between cavities 1 and 6, aiming to introduce transmission zeros to improve the out-band rejections. The originality of this letter is to consider an electrical cross-coupling embedded in the substrate via a parallel-plate waveguide. This kind of solution allows good isolation of the access cavities. The response of the filter is also highly resistant to technological dispersions. The performances of the proposed solution are compared to those of a reference filter, based on a planar electric cross-coupling, through an additional thick-film microstrip line. The proposed solution is compared with relevant examples from the literature.