The present invention relates to a chemical deposition raw material including a heterogeneous polynuclear complex in which a cyclopentadienyl and a carbonyl are coordinated to a first transition metal and a second transition metal as central metals, the chemical deposition raw material being represented by the following formula. In the following formula, the first transition metal (M1) and the second transition metal (M2) are mutually different. The number of cyclopentadienyls (L) is 1 or more and 2 or less, and to the cyclopentadienyl is coordinated one of a hydrogen atom and an alkyl group with a carbon number of 1 or more and 5 or less as each of substituents R1 to R5. With the chemical deposition raw material of the present invention, a composite metal thin film or a composite metal compound thin film containing plural metals can be formed from a single raw material.