Abstract: [Task] The present invention aims to provide a vacuum capacitor instrument voltage transformer by which current and voltage can be much precisely measured. [Means for achieving task] The means is so made that a main capacitor portion 8 and a voltage dividing capacitor portion 10 are installed in a earthed vacuum vessel, a main ground circuit 30 is provided through which a leak current I2 flows from an outer surface of the primary line-path side vacuum vessel to the earth E, and a voltage dividing ground circuit 31 is provided through which a leak current I11 flows to the earth E through a voltage dividing insulating cylindrical member 11 that is disposed between an earthed portion and each of the main capacitor portion and the voltage dividing capacitor portion.