A transparent PS-b-P4VP copolymer/SWNTs nanocomposite film is used as both source and drain electrode in a pentacene OTFT with transmittance and electric resistance values of 85% and 6000 Omega/square, respectively. The low electric resistance of the film is achieved by the selective doping of HAuCl4 in P4VP cores of the self-assembled block copolymer micelles, which simultaneously provides sufficient stability for the SWNTs suspension.