The prevention of physical aging of thin-film composite membranes based on PTMSP by the introduction of porous aromatic framework particles (PAF-11) was studied. A number of the thin-film composite (TFC) membranes with a varied thickness of the selective layer of 1.7-6.8 mu m were fabricated, and its gas transport properties were monitored during up to 650 days at ambient temperature. Among all studied TFC membranes, TFC/6.8/PAF sample provided better stability of gas permeance by retaining of 0.19, 0.24 and 0.30 from its original values for N-2, O-2, and CO2, respectively. The best gas permeance for the stabilized aged TFC membrane were 300 (N-2), 500 (O-2) and 1900 GPU (CO2), and the ideal selectivity of 1.8 and 6.9 for the pair of O-2/N-2 and CO2/N-2, respectively. It was shown that the gas selectivity of stabilized TFC membranes could be varied from 6.7 to 17 for (CO2/N-2), and from 1.7 to 2.6 for (O-2/N-2), by adjustment of the selective layer thickness.