A novel hybrid membrane was developed on the basis of poly( m-phenylene isophthalamide) (PA) by introducing an original complex modifier into the polymer; this modifier consisted of equal amounts of heteroarm star macromolecules with a fullerene C 60 core (HSM) and the ionic liquid [BMIM][Tf 2N] (IL). The effect of the (HSM:IL) complex modifier on characteristics of the PA membrane was evaluated using physical, mechanical, thermal, and gas separation techniques. The structure of the PA/(HSM:IL) membrane was studied by scanning electron microscopy (SEM). Gas transport properties were determined by measuring He, O 2, N 2, and CO 2 permeation through the membranes based on PA and its composites containing a 5 wt% modifier. The permeability coefficients of all gases through the hybrid membranes were lower than the corresponding parameters for the unmodified membrane, whereas the ideal selectivity in the separation of He/N 2, CO 2/N 2, and O 2/N 2 gas pairs was higher for the hybrid membrane. The position of the PA/(HSM:IL) membrane on the Robeson's diagram for the O 2/N 2 gas pair is discussed.