A raw material for vapor deposition for producing a platinum thin film or a platinum compound thin film by a vapor deposition method. The raw material for vapor deposition includes an organoplatinum compound represented by the following formula, in which a cyclopentene-amine ligand and an alkyl ligand are coordinated to divalent platinum. The organoplatinum compound of the present invention has moderate thermal stability and can respond flexibly to severe film formation conditions, including a wider film formation area, higher throughput, and the like. (In the formula, R1, R2, and R3 are each any one of a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an amino group, an imino group, a cyano group, and an isocyano group, each having 4 or less carbon atoms, and R4 and R5 are each an alkyl group having 1 or more and 3 or less carbon atoms.)