The paper presents the results of an experimental study of trilead tetraoxide Pb3O4 binder layers and their dielectric properties. The study revealed polarisation processes in low frequency range associated with structure peculiarities in the Pb3O4 compound. The study established the dependence of dielectric properties on temperature and frequency of the applied field. The complex dielectric response of layer samples was measured under various AC drive and DC bias conditions. The paper provides an explanation for the influence of the simultaneous AC and DC voltages on dipole and Maxwell–Wagner polarisation in Pb3O4. It is assumed that there is an impact of interfacial barriers in the polycrystalline structure. The paper discusses the role of lone pair (LP) electrons Pb2+ in polarisation properties of trilead tetraoxide compound.