An organometallic complex catalyst for use in a cross-coupling reaction, which has a structure represented by the following formula: wherein, in the M is a coordination center and represents any one of metal atoms selected from the group consisting of Pd, Pt, Rh, Ru and Cu, or an ion thereof; R 1, R 2 and R 3 may be the same or different, and each represents at least one substituent selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, alkenyl group, an alkynyl group and an aryl group; R 4, R 5, R 6 and R 7 may be the same or different, and each represents at least one substituent selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkenyl group, an alkynyl group, an aryl group, a hydroxy group, hydroxylate group, a thiocarboxyl group, a dithiocarboxyl group, a sulfo group, a sulfino group, an oxycarbonyl group, a carbamoyl group, a hydrazinocarbonyl group, an amidino group, a cyano group, an isocyano group, a cyanato group, an isocyanato group, a thiocyanato group, an isothiocyanato group, a formyl group, an oxo group, a thioformyl group, a thioxo group, a mercapto group, an amino group, an imino group, a hydrazino group, an aryloxy group, a sulfide group, a nitro group and a silyl group; X represents a halogen atom which is capable of coordinating to the coordination center M; R 8 represents a substituent having a π bond and 3 to 20 carbon atoms which is capable of coordinating to the coordination center M; provided that, with regard to electron-donating property with respect to the coordination center M, R 1, R 2, R 3, R 4, R 5, R 6 and R 7 are so combined and arranged that a TEP value (Tolman electronic parameter) [cm -1] obtained by an infrared spectroscopy of a ligand having a nitrogen-containing heterocyclic carbene structure represented by the following formula which contains R 1 to R 7, shifts toward a high frequency side compared to the TEP value [cm -1] of a ligand represented by the formula. wherein, in the formula, R 1, R 2, R 3, R 4, R 5, R 6 and R 7 represent the same substituents as R 1, R 2, R 3, R 4, R 5, R 6 and R 7 in the formula, and in the formula, R 4, R 5, R 6 and R 7 represent the same substituents as R 4, R 5, R 6 and R 7 in the formula. M is a coordination center and represents any one of metal atoms selected from the group consisting of Pd, Pt, Rh, Ru and Cu, or an ion thereof; R 1, R 2 and R 3 may be the same or different, and each represents at least one substituent selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, alkenyl group, an alkynyl group and an aryl group; R 4, R 5, R 6 and R 7 may be the same or different, and each represents at least one substituent selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkenyl group, an alkynyl group, an aryl group, a hydroxy group, hydroxylate group, a thiocarboxyl group, a dithiocarboxyl group, a sulfo group, a sulfino group, an oxycarbonyl group, a carbamoyl group, a hydrazinocarbonyl group, an amidino group, a cyano group, an isocyano group, a cyanato group, an isocyanato group, a thiocyanato group, an isothiocyanato group, a formyl group, an oxo group, a thioformyl group, a thioxo group, a mercapto group, an amino group, an imino group, a hydrazino group, an aryloxy group, a sulfide group, a nitro group and a silyl group; X represents a halogen atom which is capable of coordinating to the coordination center M; R 8 represents a substituent having a π bond and 3 to 20 carbon atoms which is capable of coordinating to the coordination center M; provided that, with regard to electron-donating property with respect to the coordination center M, R 1, R 2, R 3, R 4, R 5, R 6 and R 7 are so combined and arranged that a TEP value (Tolman electronic parameter) [cm -1] obtained by an infrared spectroscopy of a ligand having a nitrogen-containing heterocyclic carbene structure represented by the following formula which contains R 1 to R 7, shifts toward a high frequency side compared to the TEP value [cm -1] of a ligand represented by the formula. in the formula, R 1, R 2, R 3, R 4, R 5, R 6 and R 7 represent the same substituents as R 1, R 2, R 3, R 4, R 5, R 6 and R 7 in the formula, and in the formula, R 4, R 5, R 6 and R 7 represent the same substituents as R 4, R 5, R 6 and R 7 in the formula.