Films of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) pure and modified by the hybrid star‐shaped polymer (1; 3 and 5% wt.) consisting of fullerene C60 core with the grafted arms of polystyrene (PS) and diblock copolymer of 2‐vinylpyridine (2VP) and tert‐butyl methacrylate (TBMA) have been prepared and analyzed by small‐angle neutron scattering. The neutron studies of these dry samples and then the same polymers saturated with D‐methanol have demonstrated in pure PPO‐matrix the existence of a labile system of branched channels for solvent diffusion. Meanwhile in the composites a developed network of stable linear channels was observed. The investigations of membranes' morphology by scanning electron microscopy (SEM) have revealed the presence of micro‐sized domains in the samples in accordance with the neutron scattering data.