Thermal analysis of the electrical properties of materials is a materials science technique that can provide information about various phenomena (for instance phase transition, adsorption / desorption or chemical reactions) and related to different applications of materials (such as photovoltaic, catalytic, gas sensing or other engineering applications). Un-substituted manganese ferrite (MnFe2O4) and Zn-substituted manganese ferrite (Zn0.4Mn0.6Fe2O4) were synthesized by hydrothermal method. The obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and FT-IR spectroscopy, the existence of chemical phases being confirmed. Based on the impedance spectroscopy measurements (over the frequency range 20 Hz – 2 MHz) at various temperature values (ranging between 30 0C and 130 0C), a thermo-electrical analysis of the above mentioned samples was performed. The low frequency region of the electrical conductivity of samples was analyzed based on the variable range hopping model (VRH model) [1] and the high frequency region of the electrical conductivity of samples was interpreted in terms of the correlated barrier hopping model (CBH model) [2].