A rod-form high-purity polycrystalline silicon capable of preventing defects from occurring to a newly deposited silicon layer. To this end, a method of producing a rod-form high-purity polycrystalline silicon, depositing silicon on a rod-form silicon core by a thermal decomposition of a silane gas includes the steps of coating the rod-form silicon core to be used with a specific silicon layer by previously depositing any one kind of silicon layer of an amorphous silicon layer and a polycrystalline silicon layer made up of fine particles of silicon with different crystal axes from one another on a surface of the rod-form silicon core to be used by vapor growth, and depositing polycrystalline silicon by using the core coated with the specific silicon layer.