A separator is prepared based on natural and flexible eggshell membrane (ESM) for supercapacitor application. Morphology observation shows that the ESM is consisted of hierarchically ordered macroporous network. With a high decomposition temperature (>220 degrees C), enough mechanical strength (sigma(max) = 6.59 +/- 0.48 MPa, epsilon(max) = 6.98 +/- 0.31%, respectively), and low water uptake and swelling property (<10%), ESM could be a promising candidate for supercapacitor separator. As expected, the supercapacitor with ESM separator exhibits outstanding electrochemical performances, such as low resistance, quick charge-discharge ability (tau is 4.76s), and good cyclic stability (92% retention after 10,000 cycles). However, the one with PE separator shows worse properties (high resistance, low specific capacitance, etc.). This research provides new insight into the preparation of natural, low-cost and high-performance separator for supercapacitor and other applications. (C) 2012 Elsevier B.V. All rights reserved.