PROBLEM TO BE SOLVED: To provide a novel copper complex compound that is easily dissolved in solvent, has high stability even in the solvent, has a high quantum yield of light emission, and can be easily synthesized, and a fluorescent dye for medical diagnosis, a solar battery, and a light emitting element using the copper complex compound.SOLUTION: This invention provides a copper complex compound in which a phosphine ligand represented by 1,2-bis(o-methoxyphenyl phosphino) benzene is coordinated with phenylethynyl copper represented by the formula 3 (R2 is a hydrogen atom or a methyl group, and R3 is a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group).