For electronic applications it is advantageous to induce spin transitions by applying an electric field and to facilitate thereby the construction of molecule-based devices for which the magnetic state can be controlled electrically. This effect represents an important development in molecular spintronics and a basis for magnetic molecule-based quantum computing. Following this idea in the present communication we focus on crystals containing binuclear Fe-Co cyanide-bridged clusters as structural units and examine these systems placed in a dc electric field as switching molecular magnetic materials taking into account that the primary compounds Prussian blue analogues offer many possibilities to operate with their physical properties through external stimuli.   Besides the interaction of the Fe-Co cluster with the external dc electric field the developed model allows for the metal-metal electron transfer, intracluster magnetic exchange and cooperative longrange electron-deformational interaction that is examined within the mean field approach. The cluster states arising from configurations I.ls-FeII –ls-CoIII, II. ls-FeIII –ls-CoII and III. ls-FeIII –hsCoII are taken into account. The states of configurations I and II with the total cluster spin S=0 are coupled by electron transfer. The external electric dc field suppresses the electron tunneling thus leading to the appearance of a non-vanishing cluster dipole moment. The larger the parameter of electron transfer the stronger intensity of the external electric field is needed to suppress the electron transfer between the Fe and Co ions and to produce crystal polarization. Since the cluster dipole moment in localized states arising from configuration I is vanishing, while differs from zero  and it is equal in states of configurations II and III  the crystal polarization depends on the direction of the dc electric field. This effect can be also observed in the Mössbauer spectra of the Fe-Co crystal placed in the external dc electric field (Fig.1). The examination performed demonstrates an unique possibility of manipulation by the polarizability, magnetic and spectroscopic characteristics of cyanide-bridged Fe-Co clusters through the dc electric field.