In order to provide a vacuum pump motor which is free from rotation imbalance, there is provided a vacuum pump motor 10 which is connected directly to a pump main shaft 21 of a vacuum pump 20, including a motor rotor 120 which is attached directly or indirectly to the pump main shaft 21 and balance rings 127 which are attached directly or indirectly to the pump main shaft 21 at ends thereof which are spaced apart from end portions of a rotor core 123, wherein the balance rings 127 contain a material having anticorrosion properties.