Functional membranes, in which manganese meso-tetra (o-aminophenyl) porphyrin-spacer-linked polymer beads were incorporated, were prepared. The electron transfer function of the membranes was investigated by driving the conjugated redox reactions across the membranes. Consequently, it was shown that manganese porphyrin derivatives fixed to the side chains of polymer in form of beads acted as good electron carrier, while iron porphyrin, hemin, fixed to them did not. The kinetic investigation of electron tranfer supported that the hydrophilic polymer matrix and rigid side chains (spacers) were of large advantage to electron transfer function of metalloporphyrin. © 1994, The Society of Fiber Science and Technology, Japan. All rights reserved.