A stable organic charge-transfer-complex (CTC) electrode for the direct oxidation of flavoproteins has been constructed and the mode of electron transfer is described. Tetrathiafulvalene-tetracyanoquinodimeth (TTF-TCNQ) is grown at the surface of a shapable electroconductive (SEC) film (a polyanion-doped polypyrrole film) in such a way that it makes a tree-shaped crystal structure standing vertically on the surface. Glucose oxidase (GOD) is adsorbed and cross-linked under dry conditions with glutaraldehyde to fix at the surface of the CTC structure. Because of the close proximity and the favorable orientation of the enzyme at the CTC surface, a direct electron transfer between the active center of the enzyme and the crystal electrode takes place, which leads to a glucose sensor with remarkably improved performance. The kinetic parameters of the GOD/CTC/SEC electrode are reported. A mechanism of direct electron transfer is proposed.