A series of novel, microporous polymer networks (MPNs) have been generated in a simple, acid catalysed Friedel–Crafts-type self-condensation of A2B2- and A2B4-type fluorenone monomers. Two A2B4-type monomers with 2,7-bis(N,N-diphenylamino) A or 2,7-bis[4-(N,N-diphenylamino)phenyl] D substitution of the fluorenone cores lead to MPNs with high SBET surface areas of up to 1400 m2 g−1. Two MPNs made of binary monomer mixtures showed the highest Brunauer–Emmett–Teller (BET) surface areas SBET of our series (SBET of up to 1800 m2 g−1) after washing the powdery samples with supercritical carbon dioxide. Total pore volumes of up to 1.6 cm3 g−1 have been detected. It is observed that the substitution pattern of the monomers is strongly influencing the resulting physicochemical properties of the microporous polymer networks (MPNs).