PURPOSE: To efficiently manufacture a conductive composite material which has high specific conductivity and is uniform in quality by impregnating a polyester compact with an aromatic compound monomer solution using a specific solvent.

CONSTITUTION: A polyester compact is impregnated with an aromatic compound monomer solution using at least one of phenol or its derivative, benzoic acid or its derivative, benzene derivative and tetralin as a solvent. Then, it is brought into contact with a polymerization accelerating agent solution, and a conductive composite material which has high specific conductivity and is uniform in quality can be manufactured efficiently.