In this paper, a circular-polarization-sensitive absorber has been designed based on an InSb layer. The advantages of the proposed absorber rely on the magnetic circular dichroism, and the adjustable absorption property by changing the magneto-static bias and environmental temperature. The absorptance of the structure has been obtained from the 4 by 4 transfer matrix method in the THz region. Results have shown that the proposed structure has illustrated sensitivity for the absorption of right- and left-handed light polarization. The influence of different magnetic fields, environmental temperature, and different thicknesses of InSb on the tunability of left and right-handed light polarization absorption spectra have been studied. The results have illustrated the frequency of absorption peak, and its intensity can be tuned by magnetic field strength, environmental temperature, and InSb thickness.