VACUUM CAPACITOR

PROBLEM TO BE SOLVED: To mitigate the degradation of service life of a vacuum capacitor by keeping a vacuum state in a vacuum chamber without using bellows or the like and easily adjusting the electrostatic capacity. SOLUTION: A fixed electrode 4 is formed by stacking a plurality of parallel plate type electrode members 5 in the vacuum chamber 1b at intervals in a direction of the axis of the vacuum chamber 1b. A movable electrode 7 is formed by stacking a plurality of parallel plate type electrode members 8 in the vacuum chamber 1b at intervals with a movable electrode shaft 9, the respective electrode members 8 being inserted into and extracted from between the electrode members 5 of the fixed electrode 4 alternately in a non-contact state as the movable electrode shaft 9 rotates while crossing one another. In the vacuum chamber 1b, an electrostatic capacity operation unit 14 is supported rotatably which has a magnetic flux reception unit 12 fixed to the movable electrode shaft 9 on the side of a sealing member 3, and also has a magnetic flux generation unit 13 outside the sealing member 3. The electrostatic capacity operation unit 14 is rotated, and the magnetic flux reception unit 12 is rotated with magnetic attracting force to vary the crossing area between the movable electrode 7 and fixed electrode 4, thereby adjusting the electrostatic capacity. COPYRIGHT: (C)2010,JPO&INPIT