The complex dielectric constant, complex electric modulus and electrical conductivity of a Al/HgS-PVA/p-Si (MPS) capacitor were investigated via impedance spectroscopy method. Measurements have been performed within the frequency range of 2 kHz and 2 MHz between -3 V and 5 V increased by 50 mV at room temperature. Both the real and imaginary components of the complex dielectric constant and complex electric modulus were found as a strong function of frequency and voltage especially in the forward bias region. On the other hand, the dielectric loss and tangent loss versus voltage plots showed a peak behavior especially at lower frequencies in the depletion region. Similarly, real and imaginary parts of the complex electric modules versus log (frequency) plots showed a peak behavior in the depletion region, but it disappeared in the accumulation region. Additionally, three linear regions, which are classified as the low (slope= 0.74), intermediate (slope =1.09) and high (slope = 0.68) frequency ranges, have been observed in the In (conductivity) versus In (frequency) plots.