NOVELTY - A bipolar plate comprises: a metal plate; and a coating layer disposed on a surface of the metal plate. The coating layer includes a polymer of an oxazine-based compound and a conducting material.    USE - For a fuel cell (claimed).    ADVANTAGE - The polymer of the oxazine-based compound, which is coated on the surface of the metal layer together with the conducting material, is resistant to acid. Thus, the bipolar plate has excellent electrical conductivity, has good excellent resistance to acid, and improved resistance to corrosion.    DETAILED DESCRIPTION - A bipolar plate comprises: a metal plate; and a coating layer disposed on a surface of the metal plate. The coating layer includes a polymer of an oxazine-based compound and a conducting material. The oxazine-based compound comprises at least one compound selected from compounds of formulae (I) to (VI).    R1 to R4=T1 or 4-20C carbon ring group (both optionally substituted), H, halo, hydroxyl or cyano;    T1=1-20C alkyl, 1-20C alkoxy, 2-20C alkenyl, 2-20C alkynyl, 6-20C aryl, 6-20C aryloxy, 2-20C heteroaryl, 2-20C heteroaryloxy, 4-20C carbocyclic alkyl or 2-20C heterocyclic;    R5 and R5c=T1, 7-20C arylalkyl, 2-20C heteroarylalkyl, 4-20C carbocyclic, or 2-20C heterocyclic alkyl (all optionally substituted);    R6=1-20C alkylene, 2-20C alkenylene, 2-20C alkynylene, 6-20C arylene, 2-20C heteroarylene (all optionally substituted) , -C(=O)- or -SO2-;    A', B', C', D' and E'=C or N;    R1a+R2a=a ring (preferably 6-10C carbon ring, optionally fused 3-10C heteroaryl, or optionally fused 3-10C heterocyclic);    A1=1-20C heterocyclic, 4-20C cycloalkyl or 1-20C alkyl (all optionally substituted);    R'1 to R'8=H, 1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy, 1-20C heteroaryl, 1-20C heteroaryloxy, 4-20C cycloalkyl, 1-20C heterocyclic, halo, cyano, or hydroxyl;    R1b and R2b=1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy or a group of formula (Va);    R3b=T2 or H;    T2=6-20C aryl, 6-20C aryloxy, 1-20C heteroaryl, 1-20C heteroaryloxy, 4-20C carbon ring group, or 1-20C heterocyclic (all optionally halogenated), 1-20C alkyl or 1-20C alkoxy;    at least two adjacent groups selected from R2d, R3d and R4d are linked together=a group of formula asterisk-O-CH2-N(R1c)-CH2-asterisk (iia);    R5d, R6d and R7d=T2 or H;or    at least two adjacent groups selected from R5d, R6d and R7d are linked together=a group of formula (iia);    R2d, R3d and R4d=T2;    R1c=T1, 7-20C arylalkyl, 2-20C heteroarylalkyl, 4-20C carbocyclic group, or 2-20C heterocyclic alkyl group (all optionally substituted);    asterisk=sites at which at least two adjacent groups selected from R2d, R3d and R4d and at least two adjacent groups selected from R5d, R6d and R7d are linked, respectively.    One or two of A', B', C', D' and E' is N and the others are C; or all are C. At least one of A1 and R'1 to R'8 comprises a benzoxazine group. An INDEPENDENT CLAIM is included for the preparation of the bipolar plate involving: coating a surface of a metal plate with a coating layer forming composition comprising at least one oxazine-based compound (I) to (VI), a conducting material, and a solvent; and thermally treating the metal plate coated with the coating layer forming composition.