Recently the antiferroelectric liquid crystal compound (MHPOPB), synthesized in the Institute of Chemistry, Military University of Technology (Warsaw), has been studied by means of low frequency dielectric spectroscopy. This compound shows a very broad temperature range of chiral smectic C subphases: the SmC α *, the SmC β *, and the SmC γ * in the cooling process. The dielectric characteristics of these subphases are presented. In the SmC α * phase only a weak Goldstone mode was observed. In the SmC β * phase a relaxation process of characteristic antiferroelectric ordering was observed. In the SmC γ * phase a ferrielectric Goldstone mode was registered. The temperature dependence of parameters describing these modes is also presented.