TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The electroconductive base material is carbon fiber and graphite nonwoven fabric. The curing catalyst is phosphorus-type compound. The graphite particle contains scale-like natural graphite and/or spherical natural graphite having particle diameter of 20 microns or less, and artificial graphite.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Material: The electroconductive base material is carbon fiber and graphite nonwoven fabric. The curing catalyst is phosphorus-type compound. The graphite particle contains scale-like natural graphite and/or spherical natural graphite having particle diameter of 20 microns or less, and artificial graphite.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The prepreg contains 10-40 mass% of thermosetting resin. The resin composition contains a curing catalyst and a curing initiator. The equivalence ratio of curing initiator with respect to epoxy resin based on stoichiometry is 1-1.15. Preferred Resin: The thermosetting resin contains an epoxy resin having melting point of 70-130degreesC, or phenol resin. The phenol resin is a resol type phenol resin having melting point of 70-80degreesC. EXAMPLE - EOCN-1020 (cresol novolak type epoxy resin having epoxy equivalent of 199 and melting point of 75degreesC) (in weight parts) (10.85), PSM6200 (phenol novolak resin having hydroxyl equivalent of 105) (6.43), triphenyl phosphine (0.12), SGS20A (artificial graphite having average particle diameter of 20 microns) (40), A187 (epoxy silane as coupling agent) (0.6), H1-100 (natural carnauba wax having melting point of 83degreesC) (1), and J-900 (montanic-acid bis amide having melting point of 123degreesC) (1), were mixed to obtain a resin composition. The obtained composition was impregnated into a base material, and dried at 140degreesC for 4 minutes to obtain a prepreg. A fuel cell separator was manufactured using the prepreg. The fuel cell separator had favorable moldability, electrical conductivity and bending strength.